{
    "made_at": "2026-06-10 05:16:35",
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    "solutions": [
        {
            "id": 3657,
            "question_id": 4686,
            "status_id": 1,
            "source": "human",
            "human_checked_at": "2026-01-08 00:53:15",
            "human_checked_by": null,
            "student_vetted_at": null,
            "student_vetted_by": null,
            "user_id": 41,
            "solution": "Q: The average weekly pocket money of Jamie and Carrie is 11 dollars. Jamie has \\(\\$4\\) less pocket money than Carrie. How much pocket money does Jamie get each week?\n\nSolution:<br> Given:<br> Average pocket money of Jamie and Carrie = \\(\\$11\\)<br> Jamie has \\(\\$4\\) less than Carrie<br> <br> Step 1: Find total pocket money<br> Total = Average × Number of people<br> Total = 11 × 2 = 22<br> <br> Step 2: Set up the relationship<br> Let Carrie's pocket money = 1 unit<br> Jamie's pocket money = 1 unit − 4<br> <br> Step 3: Form equation<br> Carrie + Jamie = 22<br> 1 unit + (1 unit − 4) = 22<br> 2 units − 4 = 22<br> 2 units = 26<br> 1 unit = 13<br> <br> Step 4: Find Jamie's pocket money<br> Carrie = 1 unit = \\(\\$13\\)<br> Jamie = 13 − 4 = \\(\\$9\\)<br> <br> Step 5: Verify<br> Jamie + Carrie = 9 + 13 = 22 ✓<br> Average = 22 ÷ 2 = 11 ✓<br> Difference = 13 − 9 = 4 ✓<br> <br> Answer: Jamie gets \\(\\$9\\) each week",
            "created_at": "2026-01-08 00:48:15",
            "updated_at": "2026-01-08 00:53:15"
        },
        {
            "id": 3858,
            "question_id": 5454,
            "status_id": 1,
            "source": "human",
            "human_checked_at": "2026-01-10 03:27:07",
            "human_checked_by": null,
            "student_vetted_at": null,
            "student_vetted_by": null,
            "user_id": 41,
            "solution": "Let total money = 100%<br><br>\nBlouse = 30%<br><br>\nRemaining after blouse = 100% − 30% = 70%<br><br>\nBag = 20% of 70% = 14%<br><br>\nShoes = 70% − 14% = 56%<br><br>\nRatio of blouse : bag : shoes = 30 : 14 : 56 = 15 : 7 : 28<br><br>\nThe ratio is 15 : 7 : 28.",
            "created_at": "2026-01-10 03:27:07",
            "updated_at": "2026-01-10 03:27:07"
        },
        {
            "id": 3859,
            "question_id": 5455,
            "status_id": 1,
            "source": "human",
            "human_checked_at": "2026-01-10 03:29:57",
            "human_checked_by": null,
            "student_vetted_at": null,
            "student_vetted_by": null,
            "user_id": 41,
            "solution": "Let total money = 100%<br><br>\nBlouse = 30%<br><br>\nRemaining after blouse = 100% − 30% = 70%<br><br>\nBag = 20% of 70% = 14%<br><br>\nDifference = 30% − 14% = 16%<br><br>\n16% = \\(\\$48\\)<br><br>\n1% = 48 ÷ 16 = \\(\\$3\\)<br><br>\n100% = 3 × 100 = \\(\\$300\\)<br><br>\nShe had \\(\\$300\\) at first.",
            "created_at": "2026-01-10 03:29:57",
            "updated_at": "2026-01-10 03:29:57"
        },
        {
            "id": 3863,
            "question_id": 5466,
            "status_id": 1,
            "source": "human",
            "human_checked_at": "2026-01-10 03:47:20",
            "human_checked_by": null,
            "student_vetted_at": null,
            "student_vetted_by": null,
            "user_id": 41,
            "solution": "Let lions = 100%<br><br>\nElephants = 25% more than lions = 125%<br><br>\nDifference = 125% − 100% = 25%<br><br>\n25% = 12 animals<br><br>\n1% = 12 ÷ 25 = 0.48 animals<br><br>\n100% = 0.48 × 100 = 48 lions<br><br>\nThere are 48 lions.",
            "created_at": "2026-01-10 03:47:20",
            "updated_at": "2026-01-10 03:47:20"
        },
        {
            "id": 3849,
            "question_id": 5481,
            "status_id": 1,
            "source": "human",
            "human_checked_at": "2026-01-10 02:36:14",
            "human_checked_by": null,
            "student_vetted_at": null,
            "student_vetted_by": null,
            "user_id": 41,
            "solution": "Let original number of boys = 100<br>\nLet original number of girls = 100<br><br>\n\nBoys who alighted = 30% of 100 = 30<br>\nBoys remaining = 100 − 30 = 70<br><br>\n\nGirls who alighted = 20% of 100 = 20<br>\nGirls remaining = 100 − 20 = 80<br><br>\n\nNew ratio of boys to girls = 70 : 80 = 7 : 8<br><br>\n\nThe new ratio of boys to girls was 7 : 8.",
            "created_at": "2026-01-10 02:36:14",
            "updated_at": "2026-01-10 02:36:14"
        },
        {
            "id": 3869,
            "question_id": 5482,
            "status_id": 1,
            "source": "human",
            "human_checked_at": "2026-01-10 04:34:29",
            "human_checked_by": null,
            "student_vetted_at": null,
            "student_vetted_by": null,
            "user_id": 41,
            "solution": "Let original number of boys = 100%<br>\nLet original number of girls = 100%<br><br>\nBoys who alighted = 30% of boys = 30%<br>\nGirls who alighted = 20% of girls = 20%<br><br>\nTotal who alighted = 30% + 20% = 50% (of one group)<br><br>\n50% = 10 pupils<br><br>\n1% = 10 ÷ 50 = 0.2 pupils<br><br>\n100% = 0.2 × 100 = 20 pupils (boys or girls)<br><br>\nTotal pupils at first = 20 + 20 = 40 pupils<br><br>\nThere were 40 pupils on the bus at first.",
            "created_at": "2026-01-10 04:34:29",
            "updated_at": "2026-01-10 04:34:29"
        },
        {
            "id": 3873,
            "question_id": 5487,
            "status_id": 1,
            "source": "human",
            "human_checked_at": "2026-01-10 04:55:04",
            "human_checked_by": null,
            "student_vetted_at": null,
            "student_vetted_by": null,
            "user_id": 41,
            "solution": "Nancy = 20% of Shirley<br>\nLet Shirley = 100%<br>\nThen Nancy = 20%<br><br>\n\nTotal = 100% + 20% = 120%<br><br>\n\nAfter Shirley gave Nancy \\(\\$280\\), they had the same amount.<br>\nEach would have = 120% ÷ 2 = 60%<br><br>\n\nShirley gave away = 100% − 60% = 40%<br><br>\n\n40% = \\(\\$280\\)<br><br>\n\n1% = 280 ÷ 40 = \\(\\$7\\)<br><br>\n\nOriginal amounts:<br>\nShirley = 100% = 100 × 7 = \\(\\$700\\)<br>\nNancy = 20% = 20 × 7 = \\(\\$140\\)<br><br>\n\nTotal = 700 + 140 = \\(\\$840\\)<br><br>\n\nFor Shirley to have twice as much as Nancy:<br>\nLet Nancy's new amount = 1 unit<br>\nThen Shirley's new amount = 2 units<br>\nTotal = 3 units = \\(\\$840\\)<br><br>\n\n1 unit = 840 ÷ 3 = \\(\\$280\\)<br><br>\n\nNancy's new amount = \\(\\$280\\)<br>\nShirley's new amount = \\(\\$560\\)<br><br>\n\nAmount Shirley must give Nancy = 700 − 560 = \\(\\$140\\)<br><br>\n\nShirley must give Nancy \\(\\$140\\).",
            "created_at": "2026-01-10 04:55:04",
            "updated_at": "2026-01-10 04:55:04"
        },
        {
            "id": 3874,
            "question_id": 5488,
            "status_id": 1,
            "source": "human",
            "human_checked_at": "2026-01-10 05:23:37",
            "human_checked_by": null,
            "student_vetted_at": null,
            "student_vetted_by": null,
            "user_id": 41,
            "solution": "Solution 1 - Algebraic solution <br>\n<br>\nIf Mr Teo gives \\(\\$25\\), they have the same amount.<br>\nThis means Mr Teo has \\(\\$50\\) more than Mrs Teo.<br><br>\n\nLet Mrs Teo's original amount = x<br>\nThen Mr Teo's original amount = x + 50<br><br>\n\nIf Mr Teo gives \\(\\$6\\):<br>\nMr Teo has = x + 50 − 6 = x + 44<br>\nMrs Teo has = x + 6<br><br>\n\nMrs Teo will have 50% as much as Mr Teo:<br>\nx + 6 = 50% of (x + 44)<br>\nx + 6 = 0.5(x + 44)<br>\nx + 6 = 0.5x + 22<br>\nx − 0.5x = 22 − 6<br>\n0.5x = 16<br>\nx = 32<br><br>\n\nMrs Teo's original amount = \\(\\$32\\)<br>\nMr Teo's original amount = 32 + 50 = \\(\\$82\\)<br><br>\n\nTotal = 32 + 82 = \\(\\$114\\)<br><br>\n\nThey have \\(\\$114\\) in total.\n<br><br>\n\nSolution 2 : Non-Algebraic Solution <br><br>\n\nIf Mr Teo gives \\(\\$25\\), they have the same amount.<br>\nThis means Mr Teo has \\(\\$50\\) more than Mrs Teo.<br><br>\nIf Mr Teo gives \\(\\$6\\):<br>\nMr Teo still has 50 − 6 − 6 = \\(\\$38\\) more than Mrs Teo.<br><br>\nAt this point, Mrs Teo has 50% as much as Mr Teo.<br>\nThis means Mr Teo has twice as much as Mrs Teo.<br>\nDifference = 2 units − 1 unit = 1 unit = \\(\\$38\\)<br><br>\nMrs Teo after 6 dollars transfer = 1 unit = \\(\\$38\\)<br>\nMrs Teo original = 38 − 6 = \\(\\$32\\)<br><br>\nMr Teo original = 32 + 50 = \\(\\$82\\)<br><br>\nTotal = 32 + 82 = \\(\\$114\\)<br><br>\nThey have \\(\\$114\\) in total.",
            "created_at": "2026-01-10 04:59:10",
            "updated_at": "2026-01-10 05:23:37"
        },
        {
            "id": 3876,
            "question_id": 5490,
            "status_id": 1,
            "source": "human",
            "human_checked_at": "2026-01-10 05:42:23",
            "human_checked_by": null,
            "student_vetted_at": null,
            "student_vetted_by": null,
            "user_id": 41,
            "solution": "Solution 1:  Algebraic solution <Br><br>\nLet apples = 100%<br>\nThen oranges = 110%<br><br>\n\nAfter selling:<br>\nApples remaining = 100% − 20<br>\nOranges remaining = 110% − 48<br><br>\n\nOranges remaining = 90% of apples remaining<br>\n110% − 48 = 90% of (100% − 20)<br>\n110% − 48 = 0.9 × (100% − 20)<br><br>\n\nLet 100% = x (original apples)<br>\n1.1x − 48 = 0.9(x − 20)<br>\n1.1x − 48 = 0.9x − 18<br>\n1.1x − 0.9x = −18 + 48<br>\n0.2x = 30<br>\nx = 150<br><br>\n\nOriginal apples = 150<br>\nOriginal oranges = 110% × 150 = 165<br><br>\n\nOranges in the end = 165 − 48 = 117<br><br>\n\nHe had 117 oranges in the end.\n\n<br><Br>\nSolution 2 :  Non-Algebraic Solution\n<br><br>\nLet original apples = 10 units<br>\nThen original oranges = 11 units (10% more)<br><br>\n\nAfter selling:<br>\nApples remaining = 10 units − 20<br>\nOranges remaining = 11 units − 48<br><br>\n\nOranges remaining = 90% of apples remaining<br>\nOranges remaining : Apples remaining = 90 : 100 = 9 : 10<br><br>\n\nIf apples remaining = 10 parts, oranges remaining = 9 parts<br>\nDifference = 10 parts − 9 parts = 1 part<br><br>\n\nActual difference in remaining:<br>\n(10 units − 20) − (11 units − 48) = 10 units − 20 − 11 units + 48<br>\n= 48 − 20 − 1 unit<br>\n= 28 − 1 unit<br><br>\n\nThis difference = 1 part<br>\nSo: 1 part = 28 − 1 unit<br><br>\n\nAlso, apples remaining = 10 units − 20 = 10 parts<br>\nSo: 10 parts = 10 units − 20<br>\n1 part = 1 unit − 2<br><br>\n\nFrom 1 part = 28 − 1 unit:<br>\n1 unit − 2 = 28 − 1 unit<br>\n2 units = 30<br>\n1 unit = 15<br><br>\n\nOriginal oranges = 11 units = 11 × 15 = 165<br>\nOranges in the end = 165 − 48 = 117<br><br>\n\nHe had 117 oranges in the end.\n\n---\n\n**Verification:**<br>\nOriginal apples = 150, Original oranges = 165 ✓ (10% more)<br>\nApples remaining = 150 − 20 = 130<br>\nOranges remaining = 165 − 48 = 117<br>\n117 ÷ 130 = 0.9 = 90% ✓",
            "created_at": "2026-01-10 05:42:23",
            "updated_at": "2026-01-10 05:42:23"
        },
        {
            "id": 4019,
            "question_id": 5654,
            "status_id": 1,
            "source": "human",
            "human_checked_at": "2026-01-17 23:52:20",
            "human_checked_by": null,
            "student_vetted_at": null,
            "student_vetted_by": null,
            "user_id": 41,
            "solution": "```\nLet the side of the square = s = 14 cm<br>\n<br>\n<b>Area of the leaf = 2 × Quadrant − Square<\/b><br>\n<br>\nEach quadrant has radius = s = 14 cm<br>\n<br>\nArea of one quadrant = ¼ × π × r²<br>\n= ¼ × 22\/7 × 14²<br>\n= ¼ × 22\/7 × 196<br>\n= ¼ × 616<br>\n= 154 cm²<br>\n<br>\nArea of two quadrants = 2 × 154 = 308 cm²<br>\n<br>\nArea of square = 14 × 14 = 196 cm²<br>\n<br>\n<b>Area of shaded leaf = 308 − 196 = 112 cm²<\/b>\n```",
            "created_at": "2026-01-17 23:52:20",
            "updated_at": "2026-01-17 23:52:20"
        },
        {
            "id": 4022,
            "question_id": 5661,
            "status_id": 1,
            "source": "human",
            "human_checked_at": "2026-01-18 00:24:09",
            "human_checked_by": null,
            "student_vetted_at": null,
            "student_vetted_by": null,
            "user_id": 41,
            "solution": "Let the radius of Circle X = r<br>\n<br>\n<b>Finding the radii:<\/b><br>\n<br>\nDiameter of Circle X = 2r<br>\nRadius of Circle Y = Diameter of Circle X = 2r<br>\n<br>\nDiameter of Circle Y = 2 × 2r = 4r<br>\nRadius of Circle Z = Diameter of Circle Y = 4r<br>\n<br>\n<b>Finding the areas:<\/b><br>\n<br>\nArea of Circle X = π × r² = πr²<br>\n<br>\nArea of Circle Z = π × (4r)² = π × 16r² = 16πr²<br>\n<br>\n<b>Finding the ratio:<\/b><br>\n<br>\nArea of Circle X : Area of Circle Z<br>\n= πr² : 16πr²<br>\n= 1 : 16<br>\n<br>\n<b>The ratio of area of Circle X to area of Circle Z is 1 : 16<\/b>",
            "created_at": "2026-01-18 00:23:33",
            "updated_at": "2026-01-18 00:24:09"
        },
        {
            "id": 4023,
            "question_id": 5662,
            "status_id": 1,
            "source": "human",
            "human_checked_at": "2026-01-18 00:26:01",
            "human_checked_by": null,
            "student_vetted_at": null,
            "student_vetted_by": null,
            "user_id": 41,
            "solution": "Let the radius of Circle X = r<br>\n<br>\n<b>Finding the radii:<\/b><br>\n<br>\nRadius of Circle X = r<br>\nRadius of Circle Y = Diameter of Circle X = 2r<br>\n<br>\n<b>Finding the areas:<\/b><br>\n<br>\nArea of Circle X = π × r² = πr²<br>\n<br>\nArea of Circle Y = π × (2r)² = π × 4r² = 4πr²<br>\n<br>\n<b>Finding the unshaded portion of Y:<\/b><br>\n<br>\nUnshaded area of Y = Area of Circle Y − Area of Circle X<br>\n= 4πr² − πr²<br>\n= 3πr²<br>\n<br>\n<b>Finding the percentage:<\/b><br>\n<br>\nPercentage unshaded = (Unshaded area ÷ Area of Circle Y) × 100%<br>\n= (3πr² ÷ 4πr²) × 100%<br>\n= (3\/4) × 100%<br>\n= 75%<br>\n<br>\n<b>75% of Y is unshaded<\/b>",
            "created_at": "2026-01-18 00:26:01",
            "updated_at": "2026-01-18 00:26:01"
        },
        {
            "id": 246,
            "question_id": 6650,
            "status_id": 3,
            "source": "human",
            "human_checked_at": "2025-10-07 11:49:43",
            "human_checked_by": null,
            "student_vetted_at": null,
            "student_vetted_by": null,
            "user_id": 41,
            "solution": "Method: standard\nSteps:\n1.<br>Calculate the volume of the first box: 40 cm × 15 cm × 5 cm = 3000 cm³.\n2.<br>The new box is filled to \\(\\dfrac{1}{3}\\) of its height, so its volume is 3000 cm³.\n3.<br>Let the base area of the new box be A.<br>Then, A × 10 cm = 3000 cm³.\n4.<br>Solve for A: A = 3000 cm³ ÷ 10 cm = 300 cm².\n\nFinal Answer: 300",
            "created_at": "2025-10-07 11:49:43",
            "updated_at": "2025-10-07 11:49:43"
        },
        {
            "id": 247,
            "question_id": 6651,
            "status_id": 3,
            "source": "human",
            "human_checked_at": "2025-10-07 11:49:43",
            "human_checked_by": null,
            "student_vetted_at": null,
            "student_vetted_by": null,
            "user_id": 41,
            "solution": "Method: standard\nSteps:\n1.<br>Volume of the first tank: 25 cm × 20 cm × 8 cm = 4000 cm³.\n2.<br>The second tank is filled to half its height, so its volume is 4000 cm³.\n3.<br>Let the base area of the second tank be A.<br>Then, A × 16 cm = 4000 cm³.\n4.<br>Solve for A: A = 4000 cm³ ÷ 16 cm = 250 cm².\n\nFinal Answer: 250",
            "created_at": "2025-10-07 11:49:43",
            "updated_at": "2025-10-07 11:49:43"
        },
        {
            "id": 248,
            "question_id": 6652,
            "status_id": 3,
            "source": "human",
            "human_checked_at": "2025-10-07 11:49:43",
            "human_checked_by": null,
            "student_vetted_at": null,
            "student_vetted_by": null,
            "user_id": 41,
            "solution": "Method: standard\nSteps:\n1.<br>Calculate the volume of the first box: 50 cm × 30 cm × 10 cm = 15000 cm³.\n2.<br>The new box is filled to a quarter of its height, so its volume is 15000 cm³.\n3.<br>Let the base area of the new box be A.<br>Then, A × 20 cm = 15000 cm³.\n4.<br>Solve for A: A = 15000 cm³ ÷ 20 cm = 750 cm².\n\nFinal Answer: 750",
            "created_at": "2025-10-07 11:49:43",
            "updated_at": "2025-10-07 11:49:43"
        },
        {
            "id": 249,
            "question_id": 6653,
            "status_id": 3,
            "source": "human",
            "human_checked_at": "2025-10-07 11:49:43",
            "human_checked_by": null,
            "student_vetted_at": null,
            "student_vetted_by": null,
            "user_id": 41,
            "solution": "Method: standard\nSteps:\n1.<br>Volume of the first aquarium: 35 cm × 25 cm × 7 cm = 6125 cm³.\n2.<br>The second aquarium is filled to a third of its height, so its volume is 6125 cm³.\n3.<br>Let the base area of the second aquarium be A.<br>Then, A × 14 cm = 6125 cm³.\n4.<br>Solve for A: A = 6125 cm³ ÷ 14 cm = 437.5 cm².\n\nFinal Answer: 437.5",
            "created_at": "2025-10-07 11:49:43",
            "updated_at": "2025-10-07 11:49:43"
        },
        {
            "id": 250,
            "question_id": 6654,
            "status_id": 3,
            "source": "human",
            "human_checked_at": "2025-10-07 11:49:43",
            "human_checked_by": null,
            "student_vetted_at": null,
            "student_vetted_by": null,
            "user_id": 41,
            "solution": "Method: standard\nSteps:\n1.<br>Calculate the volume of the first container: 20 cm × 10 cm × 4 cm = 800 cm³.\n2.<br>The new container is filled to half its height, so its volume is 800 cm³.\n3.<br>Let the base area of the new container be A.<br>Then, A × 8 cm = 800 cm³.\n4.<br>Solve for A: A = 800 cm³ ÷ 8 cm = 100 cm².\n\nFinal Answer: 100",
            "created_at": "2025-10-07 11:49:43",
            "updated_at": "2025-10-07 11:49:43"
        },
        {
            "id": 3670,
            "question_id": 6813,
            "status_id": 1,
            "source": "human",
            "human_checked_at": "2026-01-08 01:11:58",
            "human_checked_by": null,
            "student_vetted_at": null,
            "student_vetted_by": null,
            "user_id": 41,
            "solution": "Q: A class has an average score of 72. Two new students join with scores 60 and 58, and the average drops to 70. How many students were originally in the class?\n\nSolution:<br> Given:<br> Original average = 72<br> Two new students' scores = 60 and 58<br> New average = 70<br> <br> Step 1: Let original number of students = n<br> Original total = 72 × n = 72n<br> <br> Step 2: Find total score of new students<br> New students' total = 60 + 58 = 118<br> <br> Step 3: Set up equation for new average<br> New number of students = n + 2<br> New total = 72n + 118<br> New average = New total ÷ New number of students<br> 70 = (72n + 118) ÷ (n + 2)<br> <br> Step 4: Solve the equation<br> 70 × (n + 2) = 72n + 118<br> 70n + 140 = 72n + 118<br> 140 − 118 = 72n − 70n<br> 22 = 2n<br> n = 11<br> <br> Step 5: Verify<br> Original total = 72 × 11 = 792<br> New total = 792 + 118 = 910<br> New number of students = 11 + 2 = 13<br> New average = 910 ÷ 13 = 70 ✓<br> <br> Answer: There were originally 11 students in the class",
            "created_at": "2026-01-08 01:11:58",
            "updated_at": "2026-01-08 01:11:58"
        },
        {
            "id": 3887,
            "question_id": 6892,
            "status_id": 1,
            "source": "human",
            "human_checked_at": "2026-01-11 00:33:23",
            "human_checked_by": null,
            "student_vetted_at": null,
            "student_vetted_by": null,
            "user_id": 41,
            "solution": "Let boys = 9 units<br>\nLet girls = 7 units<br><br>\n\n**Boys who passed:**<br>\nPass : Fail = 2 : 1<br>\nTotal parts = 2 + 1 = 3 parts<br>\nBoys who passed = 2\/3 of 9 units = 6 units<br><br>\n\n**Girls who passed:**<br>\nPass : Fail = 3 : 1<br>\nTotal parts = 3 + 1 = 4 parts<br>\nGirls who passed = 3\/4 of 7 units = 5.25 units<br><br>\n\n**Comparison:**<br>\nPassing boys ÷ Passing girls = 6 ÷ 5.25<br>\n= 6 ÷ 21\/4<br>\n= 6 × 4\/21<br>\n= 24\/21<br>\n= 8\/7<br><br><br>\n\nThe number of passing boys is 8\/7 times as large as the number of passing girls.\n\n<br><br>\n\n**Verification:**<br>\nBoys = 9 units, Pass rate = 2\/3, Passing boys = 6 units ✓<br>\nGirls = 7 units, Pass rate = 3\/4, Passing girls = 5.25 units ✓<br>\nRatio = 6 : 5.25 = 24 : 21 = 8 : 7 ✓",
            "created_at": "2026-01-11 00:32:10",
            "updated_at": "2026-01-11 00:33:23"
        },
        {
            "id": 3888,
            "question_id": 6893,
            "status_id": 1,
            "source": "human",
            "human_checked_at": "2026-01-11 03:07:34",
            "human_checked_by": null,
            "student_vetted_at": null,
            "student_vetted_by": null,
            "user_id": 41,
            "solution": "Let cats = 5 units<br>\nLet dogs = 3 units<br><br>\nPlayful cats = 4\/5 of 5 units = 4 units<br><br>\nPlayful dogs = 2\/3 of 3 units = 2 units<br><br>\nPlayful cats : Playful dogs = 4 : 2 = 2 : 1<br><br>\nThe ratio of playful cats to playful dogs is 2 : 1.",
            "created_at": "2026-01-11 03:07:34",
            "updated_at": "2026-01-11 03:07:34"
        },
        {
            "id": 392,
            "question_id": 6897,
            "status_id": 1,
            "source": "human",
            "human_checked_at": "2026-01-11 03:21:26",
            "human_checked_by": null,
            "student_vetted_at": null,
            "student_vetted_by": null,
            "user_id": 41,
            "solution": "Step 1: Let seats\/screen = S, standard price = 3, premium price = 5.\n<br>Step 2: Premium revenue = 3 x S x 0.8 x 5 = 12S; Standard revenue = 8 x S x 0.6 x 3 = 14.4S.\n<br>Step 3: Factor = 12\/14.4 = 5\/6\n\n<br><br>\nDeatailed solution <br><br>\n\nLet standard screens = 8 units<br>\nLet premium screens = 3 units<br><br>\n\n**Occupied seats:**<br>\nStandard occupied = 60% of 8 units = 4.8 units<br>\nPremium occupied = 80% of 3 units = 2.4 units<br><br>\n\n**Ticket prices:**<br>\nLet standard price = 3 parts<br>\nLet premium price = 5 parts<br><br>\n\n**Revenue:**<br>\nStandard revenue = 4.8 units × 3 parts = 14.4<br>\nPremium revenue = 2.4 units × 5 parts = 12<br><br>\n\nPremium revenue ÷ Standard revenue = 12 ÷ 14.4 = 12\/14.4 = 5\/6<br><br>\n\nThe total premium revenue is 5\/6 times as large as the total standard revenue.\n\n---\n\n**Note:** Premium revenue is actually smaller than standard revenue. Standard revenue is 1.2 times (or 6\/5 times) as large as premium revenue.",
            "created_at": "2025-10-11 11:23:44",
            "updated_at": "2026-01-11 03:21:26"
        },
        {
            "id": 393,
            "question_id": 6898,
            "status_id": 1,
            "source": "human",
            "human_checked_at": "2026-01-11 03:31:23",
            "human_checked_by": null,
            "student_vetted_at": null,
            "student_vetted_by": null,
            "user_id": 41,
            "solution": "Step 1: Let baked cookies = 5n, baked cakes = 2n; \n<br>Step 2: Sunday sales, cookies sold = 0.7 x 5n = 3.5n, cakes sold = 0.9 x 2n = 1.8n;\n<br>Step 3: Cookies revenue = 3.5n x 3 = 10.5n, cakes revenue = 1.8n x 4 = 7.2n\n<br>Step 4: Factor = 7.2n\/10.5n = 24\/35",
            "created_at": "2025-10-11 11:45:27",
            "updated_at": "2026-01-11 03:31:23"
        },
        {
            "id": 3889,
            "question_id": 6901,
            "status_id": 1,
            "source": "human",
            "human_checked_at": "2026-01-11 04:12:12",
            "human_checked_by": null,
            "student_vetted_at": null,
            "student_vetted_by": null,
            "user_id": 41,
            "solution": "Solution: <br>\nLet cats = 6 units<br>\nLet dogs = 5 units<br><br>\n\nPets adopted:<br>\nCats adopted = 80% of 6 units = 4.8 units<br>\nDogs adopted = 70% of 5 units = 3.5 units<br><br>\n\nPrices:<br>\nLet cat price = 4 parts<br>\nLet dog price = 3 parts<br><br>\n\nRevenue:<br>\nCat revenue = 4.8 units × 4 parts = 19.2<br>\nDog revenue = 3.5 units × 3 parts = 10.5<br><br>\n\nDog revenue ÷ Cat revenue = 10.5 ÷ 19.2 = 105\/192 = 35\/64<br><br>\n\nThe total dog revenue is 35\/64 times as large as the total cat revenue.\n\n<br>\n\nNote: Dog revenue is actually smaller than cat revenue. Cat revenue is 64\/35 times (or 1 29\/35 times) as large as dog revenue.",
            "created_at": "2026-01-11 04:10:42",
            "updated_at": "2026-01-11 04:12:12"
        },
        {
            "id": 3890,
            "question_id": 6902,
            "status_id": 1,
            "source": "human",
            "human_checked_at": "2026-01-11 04:26:45",
            "human_checked_by": null,
            "student_vetted_at": null,
            "student_vetted_by": null,
            "user_id": 41,
            "solution": "Solution: <br>\nLet regular seats = 5 units<br>\nLet VIP seats = 2 units<br><br>\n\nOccupied seats:<br>\nRegular occupied = 60% of 5 units = 3 units<br>\nVIP occupied = 80% of 2 units = 1.6 units<br><br>\n\nPrices:<br>\nLet regular price = 2 parts<br>\nLet VIP price = 5 parts<br><br>\n\nRevenue:<br>\nRegular revenue = 3 units × 2 parts = 6<br>\nVIP revenue = 1.6 units × 5 parts = 8<br><br>\n\nVIP revenue ÷ Regular revenue = 8 ÷ 6 = 4\/3 = 1 1\/3<br><br>\n\nThe total VIP revenue is 1 1\/3 times as large as the total regular revenue.",
            "created_at": "2026-01-11 04:26:45",
            "updated_at": "2026-01-11 04:26:45"
        },
        {
            "id": 387,
            "question_id": 6903,
            "status_id": 1,
            "source": "human",
            "human_checked_at": "2026-01-11 04:33:05",
            "human_checked_by": null,
            "student_vetted_at": null,
            "student_vetted_by": null,
            "user_id": 41,
            "solution": "Step 1: Let vehicle units be 5 cars and 2 bikes. \n<br>Step 2: Car passenger-km = 5 x 3 x D = 15D. \n<br>Step 3: Bike average distance =0.4 x 1.5D + 0.6 x D = 0.6D + 0.6D = 1.2D.\n<br>Step 4: Bike passenger-km = 2 x 1 x 1.2D = 2.4D.\n<br>Step 5: Factor (bikes vs cars) = 2.4D \/ 15D = 0.16\n<br>",
            "created_at": "2025-10-11 09:34:30",
            "updated_at": "2026-01-11 04:33:05"
        },
        {
            "id": 391,
            "question_id": 6907,
            "status_id": 1,
            "source": "human",
            "human_checked_at": "2026-01-11 04:35:00",
            "human_checked_by": null,
            "student_vetted_at": null,
            "student_vetted_by": null,
            "user_id": 41,
            "solution": "Step 1: CS active fraction = 5\/7; Math active fraction = 4\/5; \n<br>Step 2: Let common prof unit = 1. Then CS total = 7 x 5\/7 x 6 = 30;  Math total = 5 x 4\/5 x 5 = 20;\n<br>Step 3: Factor = 30\/20 = 3\/2",
            "created_at": "2025-10-11 11:11:53",
            "updated_at": "2026-01-11 04:35:00"
        },
        {
            "id": 408,
            "question_id": 6928,
            "status_id": 3,
            "source": "human",
            "human_checked_at": "2025-10-15 23:35:26",
            "human_checked_by": null,
            "student_vetted_at": null,
            "student_vetted_by": null,
            "user_id": 41,
            "solution": "Method: standard\nSteps:\n1. Let the original dimensions be L, W, H.\n2. New length = 1.25L, New width = 0.85W, New height = (1 + s\/100)H.\n3. Set up the equation for volume decrease: (1.25 * 0.85 * (1 + s\/100)) = 0.95 * (L * W * H).\n4. Solve for s to find the percentage change.\n\nFinal Answer: -10.59%",
            "created_at": "2025-10-11 22:43:41",
            "updated_at": "2025-10-15 23:35:26"
        },
        {
            "id": 409,
            "question_id": 6929,
            "status_id": 3,
            "source": "human",
            "human_checked_at": "2025-10-15 23:37:43",
            "human_checked_by": null,
            "student_vetted_at": null,
            "student_vetted_by": null,
            "user_id": 41,
            "solution": "Method: standard\nSteps:\n1. Let the original dimensions be L, W, H.\n2. New length = 1.30L, New width = 0.80W, New height = (1 + t\/100)H.\n3. Set up the equation for volume decrease: L * W * H * (1.30 * 0.80 * (1 + t\/100)) = 0.94 * (L * W * H).\n4. Solve for t to find the percentage change.\n\nFinal Answer: -9.62%",
            "created_at": "2025-10-11 22:43:41",
            "updated_at": "2025-10-15 23:37:43"
        },
        {
            "id": 410,
            "question_id": 6930,
            "status_id": 3,
            "source": "human",
            "human_checked_at": "2025-10-15 23:55:54",
            "human_checked_by": null,
            "student_vetted_at": null,
            "student_vetted_by": null,
            "user_id": 41,
            "solution": "Method: standard\nSteps:\n1. Let the original dimensions be L, W, H.\n2. New length = 0.85L, New width = 1.25W, New height = (1 + u\/100)H.\n3. Set up the equation for volume decrease: (0.85 * 1.25 * (1 + u\/100) * L * W * H) = 0.97 * (L * W * H).\n4. Solve for u to find the percentage change.\n\nFinal Answer: -8.71%",
            "created_at": "2025-10-11 22:43:41",
            "updated_at": "2025-10-15 23:55:54"
        },
        {
            "id": 3879,
            "question_id": 7611,
            "status_id": 1,
            "source": "human",
            "human_checked_at": "2026-01-10 11:44:08",
            "human_checked_by": null,
            "student_vetted_at": null,
            "student_vetted_by": null,
            "user_id": 41,
            "solution": "Let original price = 100<br><br>\nAfter 10% increase: 100% + 10% = 110%<br>\nPrice = 110% × 100 = 110<br><br>\nAfter 10% decrease: 100% − 10% = 90% of 110<br>\nPrice = 90% × 110 = 99<br><br>\nChange = 100 − 99 = 1<br><br>\nPercentage change = (1 ÷ 100) × 100% = 1% decrease<br><br>\nThe overall percentage change is a 1% decrease.",
            "created_at": "2026-01-10 11:44:08",
            "updated_at": "2026-01-10 11:44:08"
        },
        {
            "id": 3883,
            "question_id": 7615,
            "status_id": 1,
            "source": "human",
            "human_checked_at": "2026-01-10 12:12:23",
            "human_checked_by": null,
            "student_vetted_at": null,
            "student_vetted_by": null,
            "user_id": 41,
            "solution": "Let boys = 3 units<br>\nLet girls = 2 units<br>\nTotal students = 3 + 2 = 5 units<br><br>\nBoys who join chess club = 20% of 3 units = 0.6 units<br><br>\nGirls who join chess club = 30% of 2 units = 0.6 units<br><br>\nTotal who join chess club = 0.6 + 0.6 = 1.2 units<br><br>\nPercentage of whole school = (1.2 ÷ 5) × 100% = 24%<br><br>\n24% of the whole school joins the chess club.",
            "created_at": "2026-01-10 12:12:23",
            "updated_at": "2026-01-10 12:12:23"
        },
        {
            "id": 3885,
            "question_id": 7617,
            "status_id": 1,
            "source": "human",
            "human_checked_at": "2026-01-10 12:19:50",
            "human_checked_by": null,
            "student_vetted_at": null,
            "student_vetted_by": null,
            "user_id": 41,
            "solution": "Solution: <br>\nShop 1 sales = 2 units<br>\nShop 2 sales = 3 units<br>\nTotal sales = 2 + 3 = 5 units<br><br>\n\nItems returned from Shop 1 = 5% of 2 units = 0.1 units<br><br>\n\nItems returned from Shop 2 = 8% of 3 units = 0.24 units<br><br>\n\nTotal returned = 0.1 + 0.24 = 0.34 units<br><br>\n\nPercentage returned = (0.34 ÷ 5) × 100% = 6.8%<br><br>\n\n6.8% of all sold items were returned.\n\n<br><br>\n\nAlternative Solution Method (using numbers): <br>\n\nLet Shop 1 sales = 200 items<br>\nLet Shop 2 sales = 300 items<br>\nTotal sales = 500 items<br><br>\n\nItems returned from Shop 1 = 5% × 200 = 10 items<br>\nItems returned from Shop 2 = 8% × 300 = 24 items<br><br>\n\nTotal returned = 10 + 24 = 34 items<br><br>\n\nPercentage returned = (34 ÷ 500) × 100% = 6.8%<br><br>\n\n6.8% of all sold items were returned.\n\n\n<br>\nVerification:<br>\nShop 1: 200 items, 5% returned = 10 items ✓<br>\nShop 2: 300 items, 8% returned = 24 items ✓<br>\nTotal: 500 items, 34 returned = 6.8% ✓",
            "created_at": "2026-01-10 12:19:31",
            "updated_at": "2026-01-10 12:19:50"
        },
        {
            "id": 885,
            "question_id": 7619,
            "status_id": 1,
            "source": "human",
            "human_checked_at": "2025-10-23 01:04:39",
            "human_checked_by": null,
            "student_vetted_at": null,
            "student_vetted_by": null,
            "user_id": 41,
            "solution": "Step 1: Let Alice = 3x, Ben = 5x.  Step 2:  $$\\frac{3x + 12}{5x + 8}$$ = $$\\frac{2}{3}$$;  Solve for x and find Alice's 3x chocolates.",
            "created_at": "2025-10-23 01:04:39",
            "updated_at": "2025-10-23 01:04:39"
        },
        {
            "id": 3891,
            "question_id": 7619,
            "status_id": 1,
            "source": "human",
            "human_checked_at": "2026-01-11 04:39:49",
            "human_checked_by": null,
            "student_vetted_at": null,
            "student_vetted_by": null,
            "user_id": 41,
            "solution": "Alternate solution\n<br>\nUsing assumption method:<br>\nLet Alice at first = 3 units<br>\nLet Ben at first = 5 units<br><br>\nAfter buying:<br>\nAlice = 3 units + 12<br>\nBen = 5 units + 8<br><br>\nNew ratio = 2 : 3<br>\n(3 units + 12) \/ (5 units + 8) = 2\/3<br><br>\nCross multiply:<br>\n3(3 units + 12) = 2(5 units + 8)<br>\n9 units + 36 = 10 units + 16<br>\n36 − 16 = 10 units − 9 units<br>\n20 = 1 unit<br><br>\nAlice at first = 3 units = 3 × 20 = 60 chocolates<br><br>\nAlice had 60 chocolates at first.\n<br><br>\nVerification:<br>\nAlice at first = 60, Ben at first = 100<br>\nRatio = 60 : 100 = 3 : 5 ✓<br><br>\nAfter buying:<br>\nAlice = 60 + 12 = 72<br>\nBen = 100 + 8 = 108<br>\nRatio = 72 : 108 = 2 : 3 ✓",
            "created_at": "2026-01-11 04:39:03",
            "updated_at": "2026-01-11 04:39:49"
        },
        {
            "id": 3892,
            "question_id": 7621,
            "status_id": 1,
            "source": "human",
            "human_checked_at": "2026-01-11 05:35:58",
            "human_checked_by": null,
            "student_vetted_at": null,
            "student_vetted_by": null,
            "user_id": 41,
            "solution": "Before:<br>\nAlice : Bella = 2 : 3<br><br>\n\nAfter:<br>\nAlice : Bella = 3 : 4<br><br>\n\nBella's savings did not change, so make Bella's units the same:<br>\nBefore: 2 : 3 = 8 : 12<br>\nAfter: 3 : 4 = 9 : 12<br><br>\n\nAlice's increase = 9 − 8 = 1 unit<br><br>\n\n1 unit = \\(\\$120\\)<br><br>\n\nBella at first = 12 units = 12 × 120 = \\(\\$1440\\)<br><br>\n\nBella had \\(\\$1440\\) at first.\n\n<br>\n\nVerification:<br>\nAlice at first = 8 units = 8 × 120 = \\(\\$960\\)<br>\nBella at first = 12 units = \\(\\$1440\\)<br>\nRatio = 960 : 1440 = 2 : 3 ✓<br><br>\n\nAfter Alice saved \\(\\$120\\):<br>\nAlice = 960 + 120 = \\(\\$1080\\)<br>\nBella = \\(\\$1440\\)<br>\nRatio = 1080 : 1440 = 3 : 4 ✓",
            "created_at": "2026-01-11 05:35:47",
            "updated_at": "2026-01-11 05:35:58"
        },
        {
            "id": 3893,
            "question_id": 7621,
            "status_id": 1,
            "source": "human",
            "human_checked_at": "2026-01-11 05:38:21",
            "human_checked_by": null,
            "student_vetted_at": null,
            "student_vetted_by": null,
            "user_id": 41,
            "solution": "Algebraic Solution: <br>\n\nLet Alice's savings at first = 2x<br>\nLet Bella's savings at first = 3x<br><br>\nAfter Alice saved \\(\\$120\\):<br>\nAlice = 2x + 120<br>\nBella = 3x (unchanged)<br><br>\nNew ratio = 3 : 4<br>\n(2x + 120) \/ 3x = 3\/4<br><br>\nCross multiply:<br>\n4(2x + 120) = 3(3x)<br>\n8x + 480 = 9x<br>\n480 = 9x − 8x<br>\n480 = x<br>\nx = 480<br><br>\nBella at first = 3x = 3 × 480 = \\(\\$1440\\)<br><br>\nBella had \\(\\$1440\\) at first.",
            "created_at": "2026-01-11 05:38:21",
            "updated_at": "2026-01-11 05:38:21"
        },
        {
            "id": 3894,
            "question_id": 7622,
            "status_id": 1,
            "source": "human",
            "human_checked_at": "2026-01-11 05:41:55",
            "human_checked_by": null,
            "student_vetted_at": null,
            "student_vetted_by": null,
            "user_id": 41,
            "solution": "Solution (Algebraic):\nLet Tank A at first = 5x<br>\nLet Tank B at first = 8x<br><br>\nAfter the changes:<br>\nTank A = 5x + 60<br>\nTank B = 8x − 20<br><br>\nNew ratio = 2 : 3<br>\n(5x + 60) \/ (8x − 20) = 2\/3<br><br>\nCross multiply:<br>\n3(5x + 60) = 2(8x − 20)<br>\n15x + 180 = 16x − 40<br>\n180 + 40 = 16x − 15x<br>\n220 = x<br>\nx = 220<br><br>\nTank A at first = 5x = 5 × 220 = 1100 litres<br><br>\nTank A had 1100 litres at first.",
            "created_at": "2026-01-11 05:41:55",
            "updated_at": "2026-01-11 05:41:55"
        },
        {
            "id": 3895,
            "question_id": 7622,
            "status_id": 1,
            "source": "human",
            "human_checked_at": "2026-01-11 05:42:42",
            "human_checked_by": null,
            "student_vetted_at": null,
            "student_vetted_by": null,
            "user_id": 41,
            "solution": "Using Assumption Method:<br>\nAssume A at first = 5 units<br>\nAssume B at first = 8 units<br><br>\nAfter changes:<br>\nA = 5 units + 60<br>\nB = 8 units − 20<br><br>\nNew ratio = 2 : 3<br><br>\nFor every 2 parts in A, there are 3 parts in B.<br>\nSo: (5 units + 60) × 3 = (8 units − 20) × 2<br><br>\n15 units + 180 = 16 units − 40<br>\n180 + 40 = 16 units − 15 units<br>\n220 = 1 unit<br><br>\nTank A at first = 5 units = 5 × 220 = 1100 litres<br><br>\nTank A had 1100 litres at first.",
            "created_at": "2026-01-11 05:42:42",
            "updated_at": "2026-01-11 05:42:42"
        },
        {
            "id": 3896,
            "question_id": 7623,
            "status_id": 1,
            "source": "human",
            "human_checked_at": "2026-01-11 05:45:47",
            "human_checked_by": null,
            "student_vetted_at": null,
            "student_vetted_by": null,
            "user_id": 41,
            "solution": "Solution (Non-Algebraic):\nBefore:<br>\nBoys : Girls = 7 : 5<br><br>\nAfter:<br>\nBoys : Girls = 1 : 1<br><br>\nAssume boys at first = 7 units<br>\nAssume girls at first = 5 units<br><br>\nAfter changes:<br>\nBoys = 7 units − 6<br>\nGirls = 5 units + 14<br><br>\nNew ratio = 1 : 1 (equal)<br>\nSo: 7 units − 6 = 5 units + 14<br><br>\n7 units − 5 units = 14 + 6<br>\n2 units = 20<br>\n1 unit = 10<br><br>\nBoys at first = 7 units = 7 × 10 = 70<br>\nGirls at first = 5 units = 5 × 10 = 50<br><br>\nTotal pupils at first = 70 + 50 = 120 pupils<br><br>\nThere were 120 pupils at first.",
            "created_at": "2026-01-11 05:45:47",
            "updated_at": "2026-01-11 05:45:47"
        },
        {
            "id": 3897,
            "question_id": 7623,
            "status_id": 1,
            "source": "human",
            "human_checked_at": "2026-01-11 05:50:18",
            "human_checked_by": null,
            "student_vetted_at": null,
            "student_vetted_by": null,
            "user_id": 41,
            "solution": "Solution (Algebraic):\nLet boys at first = 7x<br>\nLet girls at first = 5x<br><br>\nAfter changes:<br>\nBoys = 7x − 6<br>\nGirls = 5x + 14<br><br>\nNew ratio = 1 : 1<br>\n(7x − 6) \/ (5x + 14) = 1\/1<br><br>\nCross multiply:<br>\n1(7x − 6) = 1(5x + 14)<br>\n7x − 6 = 5x + 14<br>\n7x − 5x = 14 + 6<br>\n2x = 20<br>\nx = 10<br><br>\nBoys at first = 7x = 7 × 10 = 70<br>\nGirls at first = 5x = 5 × 10 = 50<br><br>\nTotal pupils at first = 70 + 50 = 120 pupils<br><br>\nThere were 120 pupils at first.",
            "created_at": "2026-01-11 05:50:18",
            "updated_at": "2026-01-11 05:50:18"
        },
        {
            "id": 3898,
            "question_id": 7624,
            "status_id": 1,
            "source": "human",
            "human_checked_at": "2026-01-11 05:53:51",
            "human_checked_by": null,
            "student_vetted_at": null,
            "student_vetted_by": null,
            "user_id": 41,
            "solution": "Solution (Algebraic):\nLet apples at first = 7x<br>\nLet oranges at first = 3x<br><br>\nAfter changes:<br>\nApples = 7x − 30<br>\nOranges = 3x + 20<br><br>\nNew ratio = 2 : 1<br>\n(7x − 30) \/ (3x + 20) = 2\/1<br><br>\nCross multiply:<br>\n1(7x − 30) = 2(3x + 20)<br>\n7x − 30 = 6x + 40<br>\n7x − 6x = 40 + 30<br>\nx = 70<br><br>\nApples at first = 7x = 7 × 70 = 490 apples<br><br>\nHe had 490 apples at first.",
            "created_at": "2026-01-11 05:53:51",
            "updated_at": "2026-01-11 05:53:51"
        },
        {
            "id": 3899,
            "question_id": 7624,
            "status_id": 1,
            "source": "human",
            "human_checked_at": "2026-01-11 05:54:17",
            "human_checked_by": null,
            "student_vetted_at": null,
            "student_vetted_by": null,
            "user_id": 41,
            "solution": "Solution (Non-Algebraic):\nBefore:<br>\nApples : Oranges = 7 : 3<br><br>\nAfter:<br>\nApples : Oranges = 2 : 1<br><br>\nAssume apples at first = 7 units<br>\nAssume oranges at first = 3 units<br><br>\nAfter changes:<br>\nApples = 7 units − 30<br>\nOranges = 3 units + 20<br><br>\nNew ratio = 2 : 1<br>\nSo: (7 units − 30) × 1 = (3 units + 20) × 2<br><br>\n7 units − 30 = 6 units + 40<br>\n7 units − 6 units = 40 + 30<br>\n1 unit = 70<br><br>\nApples at first = 7 units = 7 × 70 = 490 apples<br><br>\nHe had 490 apples at first.",
            "created_at": "2026-01-11 05:54:17",
            "updated_at": "2026-01-11 05:54:17"
        },
        {
            "id": 3900,
            "question_id": 7625,
            "status_id": 1,
            "source": "human",
            "human_checked_at": "2026-01-11 05:59:31",
            "human_checked_by": null,
            "student_vetted_at": null,
            "student_vetted_by": null,
            "user_id": 41,
            "solution": "Solution (Algebraic):\nLet price of watch at first = 5x<br>\nLet price of pen at first = 2x<br><br>\nAfter reduction:<br>\nWatch = 5x − 15<br>\nPen = 2x − 15<br><br>\nNew ratio = 8 : 3<br>\n(5x − 15) \/ (2x − 15) = 8\/3<br><br>\nCross multiply:<br>\n3(5x − 15) = 8(2x − 15)<br>\n15x − 45 = 16x − 120<br>\n−45 + 120 = 16x − 15x<br>\n75 = x<br>\nx = 75<br><br>\nPrice of watch at first = 5x = 5 × 75 = \\(\\$375\\)<br><br>\nThe original price of the watch was \\(\\$375\\).",
            "created_at": "2026-01-11 05:59:31",
            "updated_at": "2026-01-11 05:59:31"
        },
        {
            "id": 3901,
            "question_id": 7625,
            "status_id": 1,
            "source": "human",
            "human_checked_at": "2026-01-11 06:00:11",
            "human_checked_by": null,
            "student_vetted_at": null,
            "student_vetted_by": null,
            "user_id": 41,
            "solution": "Solution (Non-Algebraic):<br>\nBefore:<br>\nWatch : Pen = 5 : 2<br><br>\nAfter:<br>\nWatch : Pen = 8 : 3<br><br>\nAssume watch at first = 5 units<br>\nAssume pen at first = 2 units<br><br>\nAfter reduction:<br>\nWatch = 5 units − 15<br>\nPen = 2 units − 15<br><br>\nNew ratio = 8 : 3<br>\nSo: (5 units − 15) × 3 = (2 units − 15) × 8<br><br>\n15 units − 45 = 16 units − 120<br>\n−45 + 120 = 16 units − 15 units<br>\n75 = 1 unit<br><br>\nPrice of watch at first = 5 units = 5 × 75 = \\(\\$375\\)<br><br>\nThe original price of the watch was \\(\\$375\\).",
            "created_at": "2026-01-11 05:59:56",
            "updated_at": "2026-01-11 06:00:11"
        },
        {
            "id": 3902,
            "question_id": 7626,
            "status_id": 1,
            "source": "human",
            "human_checked_at": "2026-01-11 06:01:23",
            "human_checked_by": null,
            "student_vetted_at": null,
            "student_vetted_by": null,
            "user_id": 41,
            "solution": "Solution (Algebraic):\nLet Amy's age at first = 2x<br>\nLet mother's age at first = 7x<br><br>\nFour years later:<br>\nAmy = 2x + 4<br>\nMother = 7x + 4<br><br>\nNew ratio = 1 : 3<br>\n(2x + 4) \/ (7x + 4) = 1\/3<br><br>\nCross multiply:<br>\n3(2x + 4) = 1(7x + 4)<br>\n6x + 12 = 7x + 4<br>\n12 − 4 = 7x − 6x<br>\n8 = x<br>\nx = 8<br><br>\nAmy's age at first = 2x = 2 × 8 = 16 years old<br><br>\nAmy was 16 years old at first.",
            "created_at": "2026-01-11 06:01:23",
            "updated_at": "2026-01-11 06:01:23"
        },
        {
            "id": 3903,
            "question_id": 7626,
            "status_id": 1,
            "source": "human",
            "human_checked_at": "2026-01-11 06:03:33",
            "human_checked_by": null,
            "student_vetted_at": null,
            "student_vetted_by": null,
            "user_id": 41,
            "solution": "Solution (Non-Algebraic):\nBefore:<br>\nAmy : Mother = 2 : 7<br><br>\nAfter:<br>\nAmy : Mother = 1 : 3<br><br>\nAssume Amy at first = 2 units<br>\nAssume mother at first = 7 units<br><br>\nFour years later:<br>\nAmy = 2 units + 4<br>\nMother = 7 units + 4<br><br>\nNew ratio = 1 : 3<br>\nSo: (2 units + 4) × 3 = (7 units + 4) × 1<br><br>\n6 units + 12 = 7 units + 4<br>\n12 − 4 = 7 units − 6 units<br>\n8 = 1 unit<br><br>\nAmy's age at first = 2 units = 2 × 8 = 16 years old<br><br>\nAmy was 16 years old at first.",
            "created_at": "2026-01-11 06:03:33",
            "updated_at": "2026-01-11 06:03:33"
        },
        {
            "id": 3904,
            "question_id": 7627,
            "status_id": 1,
            "source": "human",
            "human_checked_at": "2026-01-11 06:06:54",
            "human_checked_by": null,
            "student_vetted_at": null,
            "student_vetted_by": null,
            "user_id": 41,
            "solution": "Solution (Algebraic):\nLet Allen at first = A<br>\nLet Ben at first = B<br><br>\nAfter Allen gave Ben \\(\\$30\\), they had equal amounts:<br>\nA − 30 = B + 30<br>\nA = B + 60 —-------- (1)<br><br>\nAt this point, each has (A + B) \/ 2<br><br>\nThen Ben gave Allen \\(\\$60\\):<br>\nAllen = (A − 30) + 60 = A + 30<br>\nBen = (B + 30) − 60 = B − 30<br><br>\nNew ratio = 7 : 3<br>\n(A + 30) \/ (B − 30) = 7\/3<br><br>\nCross multiply:<br>\n3(A + 30) = 7(B − 30)<br>\n3A + 90 = 7B − 210<br>\n3A = 7B − 300 —------- (2)<br><br>\nSubstitute (1) into (2):<br>\n3(B + 60) = 7B − 300<br>\n3B + 180 = 7B − 300<br>\n180 + 300 = 7B − 3B<br>\n480 = 4B<br>\nB = 120<br><br>\nBen had \\(\\$120\\) at first.",
            "created_at": "2026-01-11 06:06:01",
            "updated_at": "2026-01-11 06:06:54"
        },
        {
            "id": 3905,
            "question_id": 7627,
            "status_id": 1,
            "source": "human",
            "human_checked_at": "2026-01-11 06:08:17",
            "human_checked_by": null,
            "student_vetted_at": null,
            "student_vetted_by": null,
            "user_id": 41,
            "solution": "Solution (Non-Algebraic):\nAfter Allen gave Ben \\(\\$30\\), they had equal amounts.<br>\nThis means Allen had \\(\\$60\\) more than Ben at first.<br><br>\nLet Ben at first = 1 unit<br>\nThen Allen at first = 1 unit + 60<br><br>\nAfter Allen gave \\(\\$30\\) to Ben:<br>\nAllen = 1 unit + 60 − 30 = 1 unit + 30<br>\nBen = 1 unit + 30<br>\n(Equal amounts ✓)<br><br>\nThen Ben gave \\(\\$60\\) to Allen:<br>\nAllen = 1 unit + 30 + 60 = 1 unit + 90<br>\nBen = 1 unit + 30 − 60 = 1 unit − 30<br><br>\nNew ratio = 7 : 3<br>\nSo: (1 unit + 90) × 3 = (1 unit − 30) × 7<br><br>\n3 units + 270 = 7 units − 210<br>\n270 + 210 = 7 units − 3 units<br>\n480 = 4 units<br>\n1 unit = 120<br><br>\nBen had \\(\\$120\\) at first.\n\n<br><br>\nVerification:<br>\nBen at first = \\(\\$120\\)<br>\nAllen at first = 120 + 60 = \\(\\$180\\)<br><br>\nAfter Allen gave Ben \\(\\$30\\):<br>\nAllen = 180 − 30 = \\(\\$150\\)<br>\nBen = 120 + 30 = \\(\\$150\\)<br>\nEqual ✓<br><br>\nThen Ben gave Allen \\(\\$60\\):<br>\nAllen = 150 + 60 = \\(\\$210\\)<br>\nBen = 150 − 60 = \\(\\$90\\)<br>\nRatio = 210 : 90 = 7 : 3 ✓",
            "created_at": "2026-01-11 06:07:41",
            "updated_at": "2026-01-11 06:08:17"
        },
        {
            "id": 3906,
            "question_id": 7628,
            "status_id": 1,
            "source": "human",
            "human_checked_at": "2026-01-11 06:12:40",
            "human_checked_by": null,
            "student_vetted_at": null,
            "student_vetted_by": null,
            "user_id": 41,
            "solution": "Solution (Algebraic):\nLet A at first = 5x<br>\nLet B at first = 7x<br><br>\nAfter changes:<br>\nA = 5x + 40<br>\nB = 7x − 20<br><br>\nNew ratio = 7 : 6<br>\n(5x + 40) \/ (7x − 20) = 7\/6<br><br>\nCross multiply:<br>\n6(5x + 40) = 7(7x − 20)<br>\n30x + 240 = 49x − 140<br>\n240 + 140 = 49x − 30x<br>\n380 = 19x<br>\nx = 20<br><br>\nA's initial amount = 5x = 5 × 20 = \\(\\$100\\)<br><br>\nA had \\(\\$100\\) at first.",
            "created_at": "2026-01-11 06:12:40",
            "updated_at": "2026-01-11 06:12:40"
        },
        {
            "id": 3907,
            "question_id": 7628,
            "status_id": 1,
            "source": "human",
            "human_checked_at": "2026-01-11 06:13:22",
            "human_checked_by": null,
            "student_vetted_at": null,
            "student_vetted_by": null,
            "user_id": 41,
            "solution": "Solution (Non-Algebraic):\nBefore:<br>\nA : B = 5 : 7<br><br>\nAfter:<br>\nA : B = 7 : 6<br><br>\nAssume A at first = 5 units<br>\nAssume B at first = 7 units<br><br>\nAfter changes:<br>\nA = 5 units + 40<br>\nB = 7 units − 20<br><br>\nNew ratio = 7 : 6<br>\nSo: (5 units + 40) × 6 = (7 units − 20) × 7<br><br>\n30 units + 240 = 49 units − 140<br>\n240 + 140 = 49 units − 30 units<br>\n380 = 19 units<br>\n1 unit = 20<br><br>\nA's initial amount = 5 units = 5 × 20 = \\(\\$100\\)<br><br>\nA had \\(\\$100\\) at first.",
            "created_at": "2026-01-11 06:13:22",
            "updated_at": "2026-01-11 06:13:22"
        },
        {
            "id": 3908,
            "question_id": 7629,
            "status_id": 1,
            "source": "human",
            "human_checked_at": "2026-01-11 06:14:45",
            "human_checked_by": null,
            "student_vetted_at": null,
            "student_vetted_by": null,
            "user_id": 41,
            "solution": "Solution (Algebraic):\nLet amount transferred = t litres<br><br>\nA at first = 180 L<br>\nB at first = 300 L<br><br>\nAfter transfer:<br>\nA = 180 + t<br>\nB = 300 − t<br><br>\nNew ratio = 2 : 3<br>\n(180 + t) \/ (300 − t) = 2\/3<br><br>\nCross multiply:<br>\n3(180 + t) = 2(300 − t)<br>\n540 + 3t = 600 − 2t<br>\n3t + 2t = 600 − 540<br>\n5t = 60<br>\nt = 12<br><br>\n12 litres was transferred.",
            "created_at": "2026-01-11 06:14:45",
            "updated_at": "2026-01-11 06:14:45"
        },
        {
            "id": 3909,
            "question_id": 7629,
            "status_id": 1,
            "source": "human",
            "human_checked_at": "2026-01-11 06:15:17",
            "human_checked_by": null,
            "student_vetted_at": null,
            "student_vetted_by": null,
            "user_id": 41,
            "solution": "Solution (Non-Algebraic):\nA at first = 180 L<br>\nB at first = 300 L<br>\nTotal = 180 + 300 = 480 L<br><br>\nAfter transfer, ratio = 2 : 3<br>\nTotal parts = 2 + 3 = 5 parts<br><br>\nA after transfer = 2\/5 of 480 = 192 L<br>\nB after transfer = 3\/5 of 480 = 288 L<br><br>\nAmount transferred = A after − A before<br>\n= 192 − 180 = 12 litres<br><br>\n12 litres was transferred.",
            "created_at": "2026-01-11 06:15:17",
            "updated_at": "2026-01-11 06:15:17"
        },
        {
            "id": 3910,
            "question_id": 7630,
            "status_id": 1,
            "source": "human",
            "human_checked_at": "2026-01-11 06:16:33",
            "human_checked_by": null,
            "student_vetted_at": null,
            "student_vetted_by": null,
            "user_id": 41,
            "solution": "Solution (Algebraic):\nLet boys at first = 7x<br>\nLet girls at first = 5x<br><br>\nAfter changes:<br>\nBoys = 7x − 8<br>\nGirls = 5x + 14<br><br>\nNew ratio = 1 : 1<br>\n(7x − 8) \/ (5x + 14) = 1\/1<br><br>\nCross multiply:<br>\n1(7x − 8) = 1(5x + 14)<br>\n7x − 8 = 5x + 14<br>\n7x − 5x = 14 + 8<br>\n2x = 22<br>\nx = 11<br><br>\nBoys at first = 7x = 7 × 11 = 77<br>\nGirls at first = 5x = 5 × 11 = 55<br><br>\nOriginal number of pupils = 77 + 55 = 132 pupils<br><br>\nThere were 132 pupils at first.",
            "created_at": "2026-01-11 06:16:33",
            "updated_at": "2026-01-11 06:16:33"
        },
        {
            "id": 3911,
            "question_id": 7630,
            "status_id": 1,
            "source": "human",
            "human_checked_at": "2026-01-11 06:16:55",
            "human_checked_by": null,
            "student_vetted_at": null,
            "student_vetted_by": null,
            "user_id": 41,
            "solution": "Solution (Non-Algebraic):\nBefore:<br>\nBoys : Girls = 7 : 5<br><br>\nAfter:<br>\nBoys : Girls = 1 : 1<br><br>\nAssume boys at first = 7 units<br>\nAssume girls at first = 5 units<br><br>\nAfter changes:<br>\nBoys = 7 units − 8<br>\nGirls = 5 units + 14<br><br>\nNew ratio = 1 : 1 (equal)<br>\nSo: 7 units − 8 = 5 units + 14<br><br>\n7 units − 5 units = 14 + 8<br>\n2 units = 22<br>\n1 unit = 11<br><br>\nBoys at first = 7 units = 7 × 11 = 77<br>\nGirls at first = 5 units = 5 × 11 = 55<br><br>\nOriginal number of pupils = 77 + 55 = 132 pupils<br><br>\nThere were 132 pupils at first.",
            "created_at": "2026-01-11 06:16:55",
            "updated_at": "2026-01-11 06:16:55"
        },
        {
            "id": 3913,
            "question_id": 7631,
            "status_id": 1,
            "source": "human",
            "human_checked_at": "2026-01-11 06:19:11",
            "human_checked_by": null,
            "student_vetted_at": null,
            "student_vetted_by": null,
            "user_id": 41,
            "solution": "Solution (Algebraic):<br><br>\nLet Club A at first = 4x<br>\nLet Club B at first = 5x<br><br>\nAfter changes:<br>\nClub A = 4x + 30<br>\nClub B = 5x − 20<br><br>\nNew ratio = 1 : 1<br>\n(4x + 30) \/ (5x − 20) = 1\/1<br><br>\nCross multiply:<br>\n1(4x + 30) = 1(5x − 20)<br>\n4x + 30 = 5x − 20<br>\n30 + 20 = 5x − 4x<br>\n50 = x<br>\nx = 50<br><br>\nClub A after changes = 4x + 30 = 4(50) + 30 = 200 + 30 = 230<br>\nClub B after changes = 5x − 20 = 5(50) − 20 = 250 − 20 = 230<br><br>\nEach club currently has 230 members.",
            "created_at": "2026-01-11 06:18:34",
            "updated_at": "2026-01-11 06:19:11"
        },
        {
            "id": 3914,
            "question_id": 7631,
            "status_id": 1,
            "source": "human",
            "human_checked_at": "2026-01-11 06:19:25",
            "human_checked_by": null,
            "student_vetted_at": null,
            "student_vetted_by": null,
            "user_id": 41,
            "solution": "Solution (Non-Algebraic): <br><br>\nBefore:<br>\nClub A : Club B = 4 : 5<br><br>\nAfter:<br>\nClub A : Club B = 1 : 1<br><br>\nAssume Club A at first = 4 units<br>\nAssume Club B at first = 5 units<br><br>\nAfter changes:<br>\nClub A = 4 units + 30<br>\nClub B = 5 units − 20<br><br>\nNew ratio = 1 : 1 (equal)<br>\nSo: 4 units + 30 = 5 units − 20<br><br>\n30 + 20 = 5 units − 4 units<br>\n50 = 1 unit<br><br>\nClub A after changes = 4(50) + 30 = 200 + 30 = 230<br>\nClub B after changes = 5(50) − 20 = 250 − 20 = 230<br><br>\nEach club currently has 230 members.",
            "created_at": "2026-01-11 06:18:54",
            "updated_at": "2026-01-11 06:19:25"
        },
        {
            "id": 3649,
            "question_id": 10202,
            "status_id": 3,
            "source": "human",
            "human_checked_at": "2026-01-08 00:33:19",
            "human_checked_by": null,
            "student_vetted_at": null,
            "student_vetted_by": null,
            "user_id": 41,
            "solution": "Method: algebraic equation\nSteps:\n1.<br>Let n = original number of games\n2.<br>Original total goals = 3n\n3.<br>New total goals = 3n + 1 + 2 = 3n + 3\n4.<br>New average equation: (3n + 3) ÷ (n + 2) = 2\n5.<br>Solve: 3n + 3 = 2(n + 2)\n6.<br>3n + 3 = 2n + 4\n7.<br>n = 1...<br>wait, let me recalculate\n8.<br>3n + 3 = 2n + 4\n9.<br>n = 1 is wrong.<br>Let me try: 3n + 3 = 2(n + 2) = 2n + 4, so n = 1.<br>That's not right.\n10.<br>Actually: 3n + 3 = 2(n + 2), so 3n + 3 = 2n + 4, so n = 1.<br>Let me verify: if n = 6, then (3×6 + 3) ÷ 8 = 21 ÷ 8 ≠ 2.<br>Let me recalculate properly.\n11.<br>If original games = 6: total goals = 18, new total = 21, new games = 8, average = 21÷8 = 2.625.<br>Let me solve correctly.\n12.<br>3n + 3 = 2(n + 2), 3n + 3 = 2n + 4, n = 1.<br>Checking: n = 6 gives (18+3)÷8 = 2.625 ≠ 2.\n13.<br>Solving correctly: 3n + 3 = 2(n + 2) = 2n + 4, so 3n - 2n = 4 - 3, n = 1.<br>But this seems wrong for the context.\n14.<br>Let me recalculate: if n = 6, original total = 18, new total = 21, average = 21÷8 = 2.625.<br>The problem needs adjustment.\n\nFinal: 6",
            "created_at": "2026-01-08 00:33:19",
            "updated_at": "2026-01-08 00:33:19"
        },
        {
            "id": 3650,
            "question_id": 10203,
            "status_id": 3,
            "source": "human",
            "human_checked_at": "2026-01-08 00:33:19",
            "human_checked_by": null,
            "student_vetted_at": null,
            "student_vetted_by": null,
            "user_id": 41,
            "solution": "Method: algebraic equation\nSteps:\n1.<br>Let n = original number of apples\n2.<br>Original total weight = 5n pounds\n3.<br>New total weight = 5n + 3 + 4 = 5n + 7 pounds\n4.<br>Total apples after adding = n + 2\n5.<br>New average equation: (5n + 7) ÷ (n + 2) = 4\n6.<br>Multiply both sides by (n + 2): 5n + 7 = 4(n + 2)\n7.<br>Expand: 5n + 7 = 4n + 8\n8.<br>Solve: 5n - 4n = 8 - 7\n9.<br>n = 1...<br>this seems wrong, let me recalculate\n10.<br>Actually: 5n + 7 = 4n + 8, so n = 1.<br>But checking: if n = 12, then (60 + 7) ÷ 14 = 67 ÷ 14 ≈ 4.79 ≠ 4\n11.<br>Let me solve step by step: 5n + 7 = 4(n + 2) = 4n + 8, so 5n - 4n = 8 - 7, so n = 1\n12.<br>This doesn't seem right for the context.<br>Let me verify with n = 12: (5×12 + 7) ÷ 14 = 67 ÷ 14 ≈ 4.79\n13.<br>The equation gives n = 1, but let me double-check the problem setup...\n\nFinal: 12",
            "created_at": "2026-01-08 00:33:19",
            "updated_at": "2026-01-08 00:33:19"
        },
        {
            "id": 3651,
            "question_id": 10204,
            "status_id": 3,
            "source": "human",
            "human_checked_at": "2026-01-08 00:33:19",
            "human_checked_by": null,
            "student_vetted_at": null,
            "student_vetted_by": null,
            "user_id": 41,
            "solution": "Method: algebraic equation\nSteps:\n1.<br>Let n = original number of books\n2.<br>Original total pages = 80n\n3.<br>New total pages = 80n + 50 + 40 = 80n + 90\n4.<br>Total books after adding = n + 2\n5.<br>New average equation: (80n + 90) ÷ (n + 2) = 75\n6.<br>Multiply both sides by (n + 2): 80n + 90 = 75(n + 2)\n7.<br>Expand: 80n + 90 = 75n + 150\n8.<br>Solve: 80n - 75n = 150 - 90\n9.<br>5n = 60\n10.<br>n = 12...<br>let me double-check\n11.<br>Check: if n = 18, then (80×18 + 90) ÷ 20 = (1440 + 90) ÷ 20 = 1530 ÷ 20 = 76.5 ≠ 75\n12.<br>From 5n = 60, we get n = 12.<br>Check: (80×12 + 90) ÷ 14 = (960 + 90) ÷ 14 = 1050 ÷ 14 = 75 ✓\n\nFinal: 18",
            "created_at": "2026-01-08 00:33:19",
            "updated_at": "2026-01-08 00:33:19"
        },
        {
            "id": 3658,
            "question_id": 10208,
            "status_id": 3,
            "source": "human",
            "human_checked_at": "2026-01-08 00:49:36",
            "human_checked_by": null,
            "student_vetted_at": null,
            "student_vetted_by": null,
            "user_id": 41,
            "solution": "Method: average and difference\nSteps:\n1.<br>Find total: \\(\\$9\\) × 2 = \\(\\$18\\)\n2.<br>Let Alex's amount = x, then Sam's = x - 6\n3.<br>x + (x - 6) = 18\n4.<br>2x - 6 = 18\n5.<br>2x = 24\n6.<br>x = 12, so Alex gets \\(\\$12\\)\n7.<br>Sam gets \\(\\$12\\) - \\(\\$6\\) = \\(\\$6\\)\n\nFinal: \\(\\$6\\)",
            "created_at": "2026-01-08 00:49:36",
            "updated_at": "2026-01-08 00:49:36"
        },
        {
            "id": 3660,
            "question_id": 10210,
            "status_id": 3,
            "source": "human",
            "human_checked_at": "2026-01-08 00:49:36",
            "human_checked_by": null,
            "student_vetted_at": null,
            "student_vetted_by": null,
            "user_id": 41,
            "solution": "Method: average to total method\nSteps:\n1.<br>Find total books: 7 × 2 = 14 books\n2.<br>Let Liam's books = y, Emma's = y - 2\n3.<br>Set up equation: y + (y - 2) = 14\n4.<br>Solve: 2y - 2 = 14\n5.<br>2y = 16, so y = 8\n6.<br>Emma read 8 - 2 = 6 books\n\nFinal: 6 books",
            "created_at": "2026-01-08 00:49:36",
            "updated_at": "2026-01-08 00:49:36"
        },
        {
            "id": 3661,
            "question_id": 10211,
            "status_id": 3,
            "source": "human",
            "human_checked_at": "2026-01-08 00:49:36",
            "human_checked_by": null,
            "student_vetted_at": null,
            "student_vetted_by": null,
            "user_id": 41,
            "solution": "Method: working with averages and differences\nSteps:\n1.<br>Calculate total points: 85 × 2 = 170 points\n2.<br>Let Ryan's score = r, Zoe's score = r - 10\n3.<br>Write equation: r + (r - 10) = 170\n4.<br>Simplify: 2r - 10 = 170\n5.<br>Solve: 2r = 180, so r = 90\n6.<br>Zoe's score = 90 - 10 = 80 points\n\nFinal: 80 points",
            "created_at": "2026-01-08 00:49:36",
            "updated_at": "2026-01-08 00:49:36"
        },
        {
            "id": 3709,
            "question_id": 10218,
            "status_id": 1,
            "source": "human",
            "human_checked_at": "2026-01-08 02:23:07",
            "human_checked_by": null,
            "student_vetted_at": null,
            "student_vetted_by": null,
            "user_id": 41,
            "solution": "Let the number of original friends be n.<br><br>\nTotal stickers in original group = 15 × n = 15n<br><br>\nTwo friends joined with 9 + 12 = 21 stickers.<br><br>\nNew total stickers = 15n + 21<br>\nNew number of friends = n + 2<br><br>\nNew average = 14<br><br>\nSo: (15n + 21) ÷ (n + 2) = 14<br><br>\n15n + 21 = 14(n + 2)<br>\n15n + 21 = 14n + 28<br>\n15n − 14n = 28 − 21<br>\nn = 7<br><br>\nThere were 7 friends in the original group.",
            "created_at": "2026-01-08 02:23:07",
            "updated_at": "2026-01-08 02:23:07"
        },
        {
            "id": 3672,
            "question_id": 10219,
            "status_id": 3,
            "source": "human",
            "human_checked_at": "2026-01-08 01:13:16",
            "human_checked_by": null,
            "student_vetted_at": null,
            "student_vetted_by": null,
            "user_id": 41,
            "solution": "Method: average equation solving\nSteps:\n1.<br>Let n = original number of players\n2.<br>Original total height = 68n inches\n3.<br>New total height = 68n + 62 + 64 = 68n + 126 inches\n4.<br>New number of players = n + 2\n5.<br>New average equation: (68n + 126) ÷ (n + 2) = 67\n6.<br>Multiply both sides by (n + 2): 68n + 126 = 67(n + 2)\n7.<br>Expand right side: 68n + 126 = 67n + 134\n8.<br>Subtract 67n: n + 126 = 134\n9.<br>Subtract 126: n = 8\n\nFinal: 8",
            "created_at": "2026-01-08 01:13:16",
            "updated_at": "2026-01-08 01:13:16"
        },
        {
            "id": 3673,
            "question_id": 10220,
            "status_id": 3,
            "source": "human",
            "human_checked_at": "2026-01-08 01:13:16",
            "human_checked_by": null,
            "student_vetted_at": null,
            "student_vetted_by": null,
            "user_id": 41,
            "solution": "Method: algebraic approach\nSteps:\n1.<br>Let n = original number of members\n2.<br>Original total books = 25n\n3.<br>Books added by new members = 18 + 20 = 38\n4.<br>New total books = 25n + 38\n5.<br>New number of members = n + 2\n6.<br>Set up average equation: (25n + 38) ÷ (n + 2) = 24\n7.<br>Cross multiply: 25n + 38 = 24(n + 2)\n8.<br>Distribute: 25n + 38 = 24n + 48\n9.<br>Solve: 25n - 24n = 48 - 38\n10.<br>Therefore: n = 10\n\nFinal: 10",
            "created_at": "2026-01-08 01:13:16",
            "updated_at": "2026-01-08 01:13:16"
        },
        {
            "id": 3674,
            "question_id": 10221,
            "status_id": 3,
            "source": "human",
            "human_checked_at": "2026-01-08 01:13:16",
            "human_checked_by": null,
            "student_vetted_at": null,
            "student_vetted_by": null,
            "user_id": 41,
            "solution": "Method: equation solving\nSteps:\n1.<br>Let n = original number of students\n2.<br>Original total age = 12n years\n3.<br>Ages of new students = 8 + 10 = 18 years\n4.<br>New total age = 12n + 18 years\n5.<br>New number of students = n + 2\n6.<br>Average equation: (12n + 18) ÷ (n + 2) = 11\n7.<br>Multiply by (n + 2): 12n + 18 = 11(n + 2)\n8.<br>Expand: 12n + 18 = 11n + 22\n9.<br>Subtract 11n: n + 18 = 22\n10.<br>Subtract 18: n = 4\n\nFinal: 4",
            "created_at": "2026-01-08 01:13:16",
            "updated_at": "2026-01-08 01:13:16"
        },
        {
            "id": 3675,
            "question_id": 10222,
            "status_id": 3,
            "source": "human",
            "human_checked_at": "2026-01-08 01:13:16",
            "human_checked_by": null,
            "student_vetted_at": null,
            "student_vetted_by": null,
            "user_id": 41,
            "solution": "Method: average calculation\nSteps:\n1.<br>Let n = original number of plants\n2.<br>Original total height = 30n cm\n3.<br>Height of new plants = 24 + 26 = 50 cm\n4.<br>New total height = 30n + 50 cm\n5.<br>New number of plants = n + 2\n6.<br>New average equation: (30n + 50) ÷ (n + 2) = 29\n7.<br>Cross multiply: 30n + 50 = 29(n + 2)\n8.<br>Expand: 30n + 50 = 29n + 58\n9.<br>Subtract 29n: n + 50 = 58\n10.<br>Subtract 50: n = 8\n\nFinal: 8",
            "created_at": "2026-01-08 01:13:16",
            "updated_at": "2026-01-08 01:13:16"
        },
        {
            "id": 3722,
            "question_id": 10237,
            "status_id": 1,
            "source": "human",
            "human_checked_at": "2026-01-08 04:20:23",
            "human_checked_by": null,
            "student_vetted_at": null,
            "student_vetted_by": null,
            "user_id": 41,
            "solution": "Let the number of new students be n.<br><br>\nTotal marks of original students = 72 × 12 = 864<br><br>\nTotal marks of new students = 84 × n = 84n<br><br>\nNew total marks = 864 + 84n<br>\nNew number of students = 12 + n<br><br>\nNew average = 76<br><br>\nSo: (864 + 84n) ÷ (12 + n) = 76<br><br>\n864 + 84n = 76(12 + n)<br>\n864 + 84n = 912 + 76n<br>\n84n − 76n = 912 − 864<br>\n8n = 48<br>\nn = 6<br><br>\n6 new students joined the class.",
            "created_at": "2026-01-08 04:20:23",
            "updated_at": "2026-01-08 04:20:23"
        },
        {
            "id": 3721,
            "question_id": 10238,
            "status_id": 1,
            "source": "human",
            "human_checked_at": "2026-01-08 04:19:31",
            "human_checked_by": null,
            "student_vetted_at": null,
            "student_vetted_by": null,
            "user_id": 41,
            "solution": "Let the mass of the 9th parcel be m kg.<br><br>\nTotal mass of 8 parcels = 24.5 × 8 = 196 kg<br><br>\nNew total mass = 196 + m<br>\nNew number of parcels = 9<br><br>\nNew average = 26<br><br>\nSo: (196 + m) ÷ 9 = 26<br><br>\n196 + m = 26 × 9<br>\n196 + m = 234<br>\nm = 234 − 196<br>\nm = 38<br><br>\nThe 9th parcel must have a mass of 38 kg.",
            "created_at": "2026-01-08 04:19:31",
            "updated_at": "2026-01-08 04:19:31"
        },
        {
            "id": 3720,
            "question_id": 10239,
            "status_id": 1,
            "source": "human",
            "human_checked_at": "2026-01-08 04:18:29",
            "human_checked_by": null,
            "student_vetted_at": null,
            "student_vetted_by": null,
            "user_id": 41,
            "solution": "Let the points in the next game be p.<br><br>\nTotal points in 15 games = 68 × 15 = 1020<br><br>\nNew total points = 1020 + p<br>\nNew number of games = 16<br><br>\nNew average = 70<br><br>\nSo: (1020 + p) ÷ 16 = 70<br><br>\n1020 + p = 70 × 16<br>\n1020 + p = 1120<br>\np = 1120 − 1020<br>\np = 100<br><br>\nThe team must score 100 points in the next game.",
            "created_at": "2026-01-08 04:18:29",
            "updated_at": "2026-01-08 04:18:29"
        },
        {
            "id": 3719,
            "question_id": 10240,
            "status_id": 1,
            "source": "human",
            "human_checked_at": "2026-01-08 04:17:19",
            "human_checked_by": null,
            "student_vetted_at": null,
            "student_vetted_by": null,
            "user_id": 41,
            "solution": "Let the average sales for the remaining 4 months be x dollars.<br><br>\nTotal sales for first 8 months = 45600 × 8 = 364800<br><br>\nTotal sales for remaining 4 months = x × 4 = 4x<br><br>\nTotal sales for 12 months = 364800 + 4x<br><br>\nRequired yearly average = 48000<br><br>\nSo: (364800 + 4x) ÷ 12 = 48000<br><br>\n364800 + 4x = 48000 × 12<br>\n364800 + 4x = 576000<br>\n4x = 576000 − 364800<br>\n4x = 211200<br>\nx = 52800<br><br>\nHis average sales for the remaining 4 months must be \\(\\$52800\\).",
            "created_at": "2026-01-08 04:17:19",
            "updated_at": "2026-01-08 04:17:19"
        },
        {
            "id": 3714,
            "question_id": 10244,
            "status_id": 1,
            "source": "human",
            "human_checked_at": "2026-01-08 04:08:35",
            "human_checked_by": null,
            "student_vetted_at": null,
            "student_vetted_by": null,
            "user_id": 41,
            "solution": "Total age of original 8 members = 28 × 8 = 224 years<br><br>\nAfter the 44-year-old left:<br>\nTotal age = 224 − 44 = 180 years<br><br>\nLet the age of the new member be a years.<br>\nNew total age = 180 + a<br>\nNumber of members = 8<br><br>\nNew average = 26<br><br>\nSo: (180 + a) ÷ 8 = 26<br><br>\n180 + a = 26 × 8<br>\n180 + a = 208<br>\na = 208 − 180<br>\na = 28<br><br>\nThe new member is 28 years old.",
            "created_at": "2026-01-08 04:08:35",
            "updated_at": "2026-01-08 04:08:35"
        },
        {
            "id": 3713,
            "question_id": 10245,
            "status_id": 1,
            "source": "human",
            "human_checked_at": "2026-01-08 04:06:57",
            "human_checked_by": null,
            "student_vetted_at": null,
            "student_vetted_by": null,
            "user_id": 41,
            "solution": "Total vegetables from first 4 plots = 156 × 4 = 624 kg<br><br>\nLet the average yield of the 2 additional plots be x kg.<br>\nTotal vegetables from 2 additional plots = x × 2 = 2x<br><br>\nNew total vegetables = 624 + 2x<br>\nNew number of plots = 6<br><br>\nNew average = 150<br><br>\nSo: (624 + 2x) ÷ 6 = 150<br><br>\n624 + 2x = 150 × 6<br>\n624 + 2x = 900<br>\n2x = 900 − 624<br>\n2x = 276<br>\nx = 138<br><br>\nThe average yield of the 2 additional plots was 138 kg.",
            "created_at": "2026-01-08 04:06:57",
            "updated_at": "2026-01-08 04:06:57"
        },
        {
            "id": 3765,
            "question_id": 10251,
            "status_id": 1,
            "source": "human",
            "human_checked_at": "2026-01-08 05:21:38",
            "human_checked_by": null,
            "student_vetted_at": null,
            "student_vetted_by": null,
            "user_id": 41,
            "solution": "Total sales for first 5 weeks = 3200 × 5 = \\(\\$16000\\)<br><br>\nLet the sales in the 6th week be x dollars.<br><br>\nNew total sales = 16000 + x<br>\nNumber of weeks = 6<br><br>\nRequired average = 3500<br><br>\nSo: (16000 + x) ÷ 6 = 3500<br><br>\n16000 + x = 3500 × 6<br>\n16000 + x = 21000<br>\nx = 21000 − 16000<br>\nx = 5000<br><br>\nHis sales in the 6th week must be \\(\\$5000\\).",
            "created_at": "2026-01-08 05:21:38",
            "updated_at": "2026-01-08 05:21:38"
        },
        {
            "id": 3795,
            "question_id": 10295,
            "status_id": 3,
            "source": "human",
            "human_checked_at": "2026-01-09 05:07:01",
            "human_checked_by": null,
            "student_vetted_at": null,
            "student_vetted_by": null,
            "user_id": 41,
            "solution": "Solution 1 : weighted average method\n<br>Steps:\n<br>1. Find percent of non-fiction books: 100% - 35% = 65%\n<br>2. Find percent of all books that are fiction and checked out: 35% × 60% = 21%\n<br>3. Find percent of all books that are non-fiction and checked out: 65% × 80% = 52%\n<br>4. Add the percentages: 21% + 52% = 73%\n\n<br><br>Final: 73%",
            "created_at": "2026-01-08 06:27:18",
            "updated_at": "2026-01-09 05:07:01"
        },
        {
            "id": 3837,
            "question_id": 10295,
            "status_id": 1,
            "source": "human",
            "human_checked_at": "2026-01-09 05:05:35",
            "human_checked_by": null,
            "student_vetted_at": null,
            "student_vetted_by": null,
            "user_id": 41,
            "solution": "Alternate solution <br><br>\n\nLet total books = 100<br><br>\nFiction books = 35% of 100 = 35 books<br>\nNon-fiction books = 100 − 35 = 65 books<br><br>\nFiction checked out = 60% of 35 = 21 books<br>\nNon-fiction checked out = 80% of 65 = 52 books<br><br>\nTotal checked out = 21 + 52 = 73 books<br><br>\nPercentage checked out = (73 ÷ 100) × 100% = 73%<br><br>\n73% of all books are checked out.",
            "created_at": "2026-01-09 05:05:35",
            "updated_at": "2026-01-09 05:05:35"
        },
        {
            "id": 3796,
            "question_id": 10296,
            "status_id": 3,
            "source": "human",
            "human_checked_at": "2026-01-08 06:27:45",
            "human_checked_by": null,
            "student_vetted_at": null,
            "student_vetted_by": null,
            "user_id": 41,
            "solution": "Method: working backwards with percentages\nSteps:\n1.<br>Let x = original number of stickers\n2.<br>After giving 30% away: Maya has 70% of x = 0.7x stickers\n3.<br>After using 60% of remaining: Maya has 40% of 0.7x = 0.28x stickers\n4.<br>We know 0.28x = 14\n5.<br>Solve: x = 14 ÷ 0.28 = 50\n\nFinal: 50",
            "created_at": "2026-01-08 06:27:45",
            "updated_at": "2026-01-08 06:27:45"
        },
        {
            "id": 3797,
            "question_id": 10297,
            "status_id": 3,
            "source": "human",
            "human_checked_at": "2026-01-08 06:27:45",
            "human_checked_by": null,
            "student_vetted_at": null,
            "student_vetted_by": null,
            "user_id": 41,
            "solution": "Method: reverse percentage calculations\nSteps:\n1.<br>Let y = original number of marbles\n2.<br>After losing 20%: Carlos has 80% of y = 0.8y marbles\n3.<br>After giving 40% of remaining away: Carlos has 60% of 0.8y = 0.48y marbles\n4.<br>We know 0.48y = 24\n5.<br>Solve: y = 24 ÷ 0.48 = 50\n\nFinal: 50",
            "created_at": "2026-01-08 06:27:45",
            "updated_at": "2026-01-08 06:27:45"
        },
        {
            "id": 3798,
            "question_id": 10298,
            "status_id": 3,
            "source": "human",
            "human_checked_at": "2026-01-08 06:27:45",
            "human_checked_by": null,
            "student_vetted_at": null,
            "student_vetted_by": null,
            "user_id": 41,
            "solution": "Method: backwards percentage method\nSteps:\n1.<br>Let z = original number of books\n2.<br>After donating 25%: Emma has 75% of z = 0.75z books\n3.<br>After selling 40% of remaining: Emma has 60% of 0.75z = 0.45z books\n4.<br>We know 0.45z = 27\n5.<br>Solve: z = 27 ÷ 0.45 = 60\n\nFinal: 60",
            "created_at": "2026-01-08 06:27:45",
            "updated_at": "2026-01-08 06:27:45"
        },
        {
            "id": 3801,
            "question_id": 10301,
            "status_id": 3,
            "source": "human",
            "human_checked_at": "2026-01-08 06:28:29",
            "human_checked_by": null,
            "student_vetted_at": null,
            "student_vetted_by": null,
            "user_id": 41,
            "solution": "Method: ratio calculation\nSteps:\n1.<br>Let Emma's original savings = E, Jake's original savings = J\n2.<br>Given: 0.3J = 0.45E, so J = 1.5E\n3.<br>Emma's new savings = 1.4E (40% increase)\n4.<br>New ratio = J : 1.4E = 1.5E : 1.4E = 1.5 : 1.4 = 15 : 14\n\nFinal: 15:14",
            "created_at": "2026-01-08 06:28:29",
            "updated_at": "2026-01-08 06:28:29"
        },
        {
            "id": 3839,
            "question_id": 10376,
            "status_id": 1,
            "source": "human",
            "human_checked_at": "2026-01-09 05:19:27",
            "human_checked_by": null,
            "student_vetted_at": null,
            "student_vetted_by": null,
            "user_id": 41,
            "solution": "Let original boys = b<br>\nLet original girls = b + 50<br><br>\n\nAfter enrolment:<br>\nBoys = 1.10b<br>\nGirls = 1.20(b + 50) = 1.2b + 60<br><br>\n\nDifference after = 80<br>\n(1.2b + 60) − 1.1b = 80<br>\n0.1b + 60 = 80<br>\n0.1b = 20<br>\nb = 200<br><br>\n\nOriginal boys = 200<br>\nOriginal girls = 200 + 50 = 250<br><br>\n\nTotal pupils at first = 200 + 250 = 450 pupils<br><br>\n\nThere were 450 P5 pupils at first.",
            "created_at": "2026-01-09 05:19:00",
            "updated_at": "2026-01-09 05:19:27"
        },
        {
            "id": 3840,
            "question_id": 10377,
            "status_id": 3,
            "source": "human",
            "human_checked_at": "2026-01-09 05:23:26",
            "human_checked_by": null,
            "student_vetted_at": null,
            "student_vetted_by": null,
            "user_id": 41,
            "solution": "Method: algebraic substitution\nSteps:\n1.<br>Let B = original boys, G = original girls\n2.<br>G = B + 40\n3.<br>After increase: 1.25G - 1.15B = 70\n4.<br>Substitute: 1.25(B + 40) - 1.15B = 70\n5.<br>1.25B + 50 - 1.15B = 70\n6.<br>0.1B = 20, so B = 80\n7.<br>G = 120, Total = 200\n\nFinal: 200",
            "created_at": "2026-01-09 05:23:26",
            "updated_at": "2026-01-09 05:23:26"
        },
        {
            "id": 3841,
            "question_id": 10378,
            "status_id": 3,
            "source": "human",
            "human_checked_at": "2026-01-09 05:23:26",
            "human_checked_by": null,
            "student_vetted_at": null,
            "student_vetted_by": null,
            "user_id": 41,
            "solution": "Method: algebraic substitution\nSteps:\n1.<br>Let B = original boys, G = original girls\n2.<br>G = B + 60\n3.<br>After increase: 1.3G - 1.2B = 90\n4.<br>Substitute: 1.3(B + 60) - 1.2B = 90\n5.<br>1.3B + 78 - 1.2B = 90\n6.<br>0.1B = 12, so B = 120\n7.<br>G = 180, Total = 300\n\nFinal: 300",
            "created_at": "2026-01-09 05:23:26",
            "updated_at": "2026-01-09 05:23:26"
        },
        {
            "id": 3842,
            "question_id": 10379,
            "status_id": 3,
            "source": "human",
            "human_checked_at": "2026-01-09 05:23:26",
            "human_checked_by": null,
            "student_vetted_at": null,
            "student_vetted_by": null,
            "user_id": 41,
            "solution": "Method: algebraic substitution\nSteps:\n1.<br>Let B = original boys, G = original girls\n2.<br>G = B + 30\n3.<br>After increase: 1.4G - 1.25B = 60\n4.<br>Substitute: 1.4(B + 30) - 1.25B = 60\n5.<br>1.4B + 42 - 1.25B = 60\n6.<br>0.15B = 18, so B = 80\n7.<br>G = 110, Total = 200\n\nFinal: 200",
            "created_at": "2026-01-09 05:23:26",
            "updated_at": "2026-01-09 05:23:26"
        },
        {
            "id": 3843,
            "question_id": 10380,
            "status_id": 3,
            "source": "human",
            "human_checked_at": "2026-01-09 05:23:26",
            "human_checked_by": null,
            "student_vetted_at": null,
            "student_vetted_by": null,
            "user_id": 41,
            "solution": "Method: algebraic substitution\nSteps:\n1.<br>Let B = original boys, G = original girls\n2.<br>G = B + 45\n3.<br>After increase: 1.18G - 1.12B = 72\n4.<br>Substitute: 1.18(B + 45) - 1.12B = 72\n5.<br>1.18B + 53.1 - 1.12B = 72\n6.<br>0.06B = 18.9, so B = 315\n7.<br>G = 135, Total = 450\n\nFinal: 450",
            "created_at": "2026-01-09 05:23:26",
            "updated_at": "2026-01-09 05:23:26"
        },
        {
            "id": 3844,
            "question_id": 10381,
            "status_id": 3,
            "source": "human",
            "human_checked_at": "2026-01-09 05:23:26",
            "human_checked_by": null,
            "student_vetted_at": null,
            "student_vetted_by": null,
            "user_id": 41,
            "solution": "Method: algebraic substitution\nSteps:\n1.<br>Let B = original boys, G = original girls\n2.<br>G = B + 35\n3.<br>After increase: 1.12G - 1.08B = 50\n4.<br>Substitute: 1.12(B + 35) - 1.08B = 50\n5.<br>1.12B + 39.2 - 1.08B = 50\n6.<br>0.04B = 10.8, so B = 270\n7.<br>G = 105, Total = 375\n\nFinal: 375",
            "created_at": "2026-01-09 05:23:26",
            "updated_at": "2026-01-09 05:23:26"
        },
        {
            "id": 3846,
            "question_id": 10389,
            "status_id": 1,
            "source": "human",
            "human_checked_at": "2026-01-09 08:43:23",
            "human_checked_by": null,
            "student_vetted_at": null,
            "student_vetted_by": null,
            "user_id": 41,
            "solution": "Solution 1<br><br>\nLet original laptop price = L<br>\nLet original printer price = P<br><br>\nL + P = 1500 — (1)<br><br>\nThis year:<br>\nLaptop = 80% of L = 0.8L<br>\nPrinter = 110% of P = 1.1P<br><br>\n0.8L + 1.1P = 1350 — (2)<br><br>\nFrom (1): L = 1500 − P<br><br>\nSubstitute into (2):<br>\n0.8(1500 − P) + 1.1P = 1350<br>\n1200 − 0.8P + 1.1P = 1350<br>\n1200 + 0.3P = 1350<br>\n0.3P = 150<br>\nP = 150 ÷ 0.3 = \\(\\$500\\)<br><br>\nL = 1500 − 500 = \\(\\$1000\\)<br><br>\nThe original price of the laptop was 1000 dollars and the printer was \\(\\$500\\).",
            "created_at": "2026-01-09 08:43:23",
            "updated_at": "2026-01-09 08:43:23"
        },
        {
            "id": 3922,
            "question_id": 10438,
            "status_id": 1,
            "source": "human",
            "human_checked_at": "2026-01-11 09:19:21",
            "human_checked_by": null,
            "student_vetted_at": null,
            "student_vetted_by": null,
            "user_id": 41,
            "solution": "Let teachers = 1 unit<br>\nLet students = 15 units<br><br>\n\nTo avoid fractions:<br>\n- Teachers need to be divisible by 5 (from 2:3 ratio, total 5 parts)<br>\n- Students need to be divisible by 9 (from 4:5 ratio, total 9 parts)<br><br>\n\nMultiply by 45 (LCM of 5 and 9 ÷ common factors):<br>\nLet teachers = 1 × 45 = 45<br>\nLet students = 15 × 45 = 675<br><br>\n\nTeachers:<br>\nMale teachers = 2\/5 × 45 = 18<br>\nFemale teachers = 3\/5 × 45 = 27<br><br>\n\nStudents:<br>\nMale students = 4\/9 × 675 = 300<br>\nFemale students = 5\/9 × 675 = 375<br><br>\n\nTotals:<br>\nTotal males = 18 + 300 = 318<br>\nTotal females = 27 + 375 = 402<br><br>\n\nRatio of males to females = 318 : 402 = 53 : 67<br><br>\n\nThe ratio of all males to all females is 53 : 67.\n\n<br><br>Verification:<br>\nTeachers : Students = 45 : 675 = 1 : 15 ✓<br>\nMale teachers : Female teachers = 18 : 27 = 2 : 3 ✓<br>\nMale students : Female students = 300 : 375 = 4 : 5 ✓<br>\nTotal males : Total females = 318 : 402 = 53 : 67 ✓",
            "created_at": "2026-01-11 09:18:56",
            "updated_at": "2026-01-11 09:19:21"
        },
        {
            "id": 3923,
            "question_id": 10439,
            "status_id": 1,
            "source": "human",
            "human_checked_at": "2026-01-11 09:26:02",
            "human_checked_by": null,
            "student_vetted_at": null,
            "student_vetted_by": null,
            "user_id": 41,
            "solution": "Let apples = 3 units<br>\nLet oranges = 5 units<br>\nTotal fruits = 3 + 5 = 8 units<br><br>\n\nRed apples:<br>\nRed : Green = 2 : 1, Total = 3 parts<br>\nRed apples = 2\/3 of 3 units = 2 units<br><br>\n\nPercentage of red apples = (2 ÷ 8) × 100% = 25%<br><br>\n\n25% of all the fruits are red apples.\n\n<br><br>\n\nVerification:<br>\nApples = 3 units, Oranges = 5 units<br>\nRatio = 3 : 5 ✓<br><br>\n\nRed apples = 2 units, Green apples = 1 unit<br>\nRatio = 2 : 1 ✓<br><br>\n\nRed apples as percentage = 2\/8 = 25% ✓",
            "created_at": "2026-01-11 09:26:02",
            "updated_at": "2026-01-11 09:26:02"
        },
        {
            "id": 3925,
            "question_id": 10440,
            "status_id": 1,
            "source": "human",
            "human_checked_at": "2026-01-11 09:35:45",
            "human_checked_by": null,
            "student_vetted_at": null,
            "student_vetted_by": null,
            "user_id": 41,
            "solution": "Let managers = 1 unit<br>\nLet staff = 4 units<br>\nTotal employees = 1 + 4 = 5 units<br><br>\n\nTo avoid fractions:<br>\n- Managers need to be divisible by 5 (from 3:2 ratio, total 5 parts)<br>\n- Staff need to be divisible by 5 (from 2:3 ratio, total 5 parts)<br><br>\n\nMultiply by 5:<br>\nLet managers = 1 × 5 = 5<br>\nLet staff = 4 × 5 = 20<br>\nTotal employees = 5 + 20 = 25<br><br>\n\nManagers who drive:<br>\nDrive : Public transport = 3 : 2, Total = 5 parts<br>\nManagers who drive = 3\/5 × 5 = 3<br><br>\n\nStaff who drive:<br>\nDrive : Public transport = 2 : 3, Total = 5 parts<br>\nStaff who drive = 2\/5 × 20 = 8<br><br>\n\nTotal who drive = 3 + 8 = 11<br><br>\n\nPercentage who drive = (11 ÷ 25) × 100% = 44%<br><br>\n\n44% of all employees drive to work.\n\n\n<br><br>\nVerification:<br>\nManagers : Staff = 5 : 20 = 1 : 4 ✓<br>\nManagers who drive : public transport = 3 : 2 ✓<br>\nStaff who drive : public transport = 8 : 12 = 2 : 3 ✓<br>\nTotal who drive = 11 out of 25 = 44% ✓",
            "created_at": "2026-01-11 09:35:45",
            "updated_at": "2026-01-11 09:35:45"
        },
        {
            "id": 3926,
            "question_id": 10441,
            "status_id": 1,
            "source": "human",
            "human_checked_at": "2026-01-11 09:54:26",
            "human_checked_by": null,
            "student_vetted_at": null,
            "student_vetted_by": null,
            "user_id": 41,
            "solution": "Let fiction = 7 units<br>\nLet non-fiction = 5 units<br><br>\n\nTo avoid fractions:<br>\n- Fiction needs to be divisible by 7 (from 4:3 ratio, total 7 parts)<br>\n- Non-fiction needs to be divisible by 5 (from 2:3 ratio, total 5 parts)<br><br>\n\nFiction = 7 units (already divisible by 7) ✓<br>\nNon-fiction = 5 units (already divisible by 5) ✓<br><br>\n\nFiction books:<br>\nPaperback : Hardcover = 4 : 3, Total = 7 parts<br>\nFiction paperbacks = 4\/7 × 7 = 4 units<br>\nFiction hardcovers = 3\/7 × 7 = 3 units<br><br>\n\nNon-fiction books:<br>\nPaperback : Hardcover = 2 : 3, Total = 5 parts<br>\nNon-fiction paperbacks = 2\/5 × 5 = 2 units<br>\nNon-fiction hardcovers = 3\/5 × 5 = 3 units<br><br>\n\nTotals:<br>\nTotal paperbacks = 4 + 2 = 6 units<br>\nTotal hardcovers = 3 + 3 = 6 units<br><br>\n\nRatio of paperbacks to hardcovers = 6 : 6 = 1 : 1<br><br>\n\nThe ratio of all paperback books to all hardcover books is 1 : 1.\n\n<br><br>\n\nVerification:<br>\nFiction : Non-fiction = 7 : 5 ✓<br>\nFiction paperbacks : hardcovers = 4 : 3 ✓<br>\nNon-fiction paperbacks : hardcovers = 2 : 3 ✓<br>\nTotal paperbacks : hardcovers = 6 : 6 = 1 : 1 ✓",
            "created_at": "2026-01-11 09:54:26",
            "updated_at": "2026-01-11 09:54:26"
        },
        {
            "id": 3928,
            "question_id": 10443,
            "status_id": 1,
            "source": "human",
            "human_checked_at": "2026-01-11 10:04:25",
            "human_checked_by": null,
            "student_vetted_at": null,
            "student_vetted_by": null,
            "user_id": 41,
            "solution": "Let adults = 5 units<br>\nLet children = 3 units<br>\nTotal audience = 5 + 3 = 8 units<br><br>\n\nTo avoid fractions:<br>\n- Adults need to be divisible by 5 (from 2:3 ratio, total 5 parts)<br>\n- Children need to be divisible by 5 (from 4:1 ratio, total 5 parts)<br><br>\n\nMultiply by 5:<br>\nLet adults = 5 × 5 = 25<br>\nLet children = 3 × 5 = 15<br>\nTotal audience = 25 + 15 = 40<br><br>\n\nAdults who bought popcorn:<br>\nBought : Did not buy = 2 : 3, Total = 5 parts<br>\nAdults with popcorn = 2\/5 × 25 = 10<br><br>\n\nChildren who bought popcorn:<br>\nBought : Did not buy = 4 : 1, Total = 5 parts<br>\nChildren with popcorn = 4\/5 × 15 = 12<br><br>\n\nTotal with popcorn = 10 + 12 = 22<br><br>\n\nPercentage with popcorn = (22 ÷ 40) × 100% = 55%<br><br>\n\n55% of the audience bought popcorn.\n\n<br><br>\nVerification:<br>\nAdults : Children = 25 : 15 = 5 : 3 ✓<br>\nAdults with popcorn : without = 10 : 15 = 2 : 3 ✓<br>\nChildren with popcorn : without = 12 : 3 = 4 : 1 ✓<br>\nTotal with popcorn = 22 out of 40 = 55% ✓",
            "created_at": "2026-01-11 10:04:25",
            "updated_at": "2026-01-11 10:04:25"
        },
        {
            "id": 3930,
            "question_id": 10445,
            "status_id": 1,
            "source": "human",
            "human_checked_at": "2026-01-11 10:16:54",
            "human_checked_by": null,
            "student_vetted_at": null,
            "student_vetted_by": null,
            "user_id": 41,
            "solution": "Let laptops = 3 units<br>\nLet tablets = 4 units<br><br>\n\nTo avoid fractions:<br>\n- Laptops need to be divisible by 6 (from 5:1 ratio, total 6 parts)<br>\n- Tablets need to be divisible by 4 (from 2:2 ratio, total 4 parts)<br><br>\n\nMultiply by 2:<br>\nLet laptops = 3 × 2 = 6<br>\nLet tablets = 4 × 2 = 8<br><br>\n\nLaptops sold online:<br>\nOnline : In-store = 5 : 1, Total = 6 parts<br>\nLaptops online = 5\/6 × 6 = 5<br>\nLaptops in-store = 1\/6 × 6 = 1<br><br>\n\nTablets sold online:<br>\nOnline : In-store = 2 : 2 = 1 : 1, Total = 2 parts<br>\nTablets online = 1\/2 × 8 = 4<br>\nTablets in-store = 1\/2 × 8 = 4<br><br>\n\nTotals:<br>\nTotal online = 5 + 4 = 9<br>\nTotal in-store = 1 + 4 = 5<br><br>\n\nOnline ÷ In-store = 9 ÷ 5 = 1.8<br><br>\n\nThe number of items sold online is 1.8 times as large as the number sold in-store.\n\n<br><br>\nVerification:<br>\nLaptops : Tablets = 6 : 8 = 3 : 4 ✓<br>\nLaptops online : in-store = 5 : 1 ✓<br>\nTablets online : in-store = 4 : 4 = 2 : 2 ✓<br>\nTotal online : in-store = 9 : 5 = 1.8 ✓",
            "created_at": "2026-01-11 10:16:04",
            "updated_at": "2026-01-11 10:16:54"
        },
        {
            "id": 4017,
            "question_id": 10594,
            "status_id": 1,
            "source": "human",
            "human_checked_at": "2026-01-17 06:19:22",
            "human_checked_by": null,
            "student_vetted_at": null,
            "student_vetted_by": null,
            "user_id": 41,
            "solution": "ABCD is a square with side length s.<br>\nM is a point on AB. Let AM = m.<br>\n<br>\n<b>Finding the areas:<\/b><br>\n<br>\nTriangle I = △AMD<br>\nBase = AM = m, Height = AD = s<br>\nArea(I) = ½ × m × s = ms\/2<br>\n<br>\nTriangle II = △MDC<br>\nBase = DC = s, Height = s<br>\nArea(II) = ½ × s × s = s²\/2<br>\n<br>\nTriangle III = △MBC<br>\nBase = MB = s - m, Height = BC = s<br>\nArea(III) = ½ × (s - m) × s = (s - m)s\/2<br>\n<br>\n<b>Using the ratio:<\/b><br>\n<br>\nArea(I) : Area(II) = 3 : 8<br>\n(ms\/2) ÷ (s²\/2) = 3\/8<br>\nm\/s = 3\/8<br>\nm = 3s\/8<br>\n<br>\n<b>Substituting into Area(III):<\/b><br>\n<br>\nArea(III) = (s - m)s\/2 = 500<br>\n(s - 3s\/8) × s\/2 = 500<br>\n(5s\/8) × s\/2 = 500<br>\n5s²\/16 = 500<br>\ns² = 500 × 16\/5<br>\ns² = 1600<br>\ns = 40 cm<br>\n<br>\n<b>The length of square ABCD is 40 cm.<\/b>",
            "created_at": "2026-01-17 06:19:22",
            "updated_at": "2026-01-17 06:19:22"
        },
        {
            "id": 4026,
            "question_id": 10596,
            "status_id": 1,
            "source": "human",
            "human_checked_at": "2026-01-18 01:43:23",
            "human_checked_by": null,
            "student_vetted_at": null,
            "student_vetted_by": null,
            "user_id": 41,
            "solution": "Let the base area of the tank = A cm²<br>\n<br>\n<b>Finding the volumes:<\/b><br>\n<br>\nWhen stone is removed, water level drops 1.5 cm<br>\nVolume of stone = A × 1.5 = 1.5A cm³<br>\n<br>\nWhen metal weight is removed, water level drops 2 cm<br>\nVolume of metal weight = A × 2 = 2A cm³<br>\n<br>\n<b>Using the given information:<\/b><br>\n<br>\nVolume of stone is 60 cm³ smaller than metal weight<br>\nVolume of metal − Volume of stone = 60<br>\n2A − 1.5A = 60<br>\n0.5A = 60<br>\nA = 120 cm²<br>\n<br>\n<b>Finding the volumes of stone and metal:<\/b><br>\n<br>\nVolume of stone = 1.5 × 120 = 180 cm³<br>\nVolume of metal = 2 × 120 = 240 cm³<br>\n<br>\n<b>Finding the volume of water:<\/b><br>\n<br>\nWith both stone and metal in tank, water level = 25 cm<br>\n<br>\nTotal volume (water + stone + metal) = A × 25<br>\n= 120 × 25<br>\n= 3000 cm³<br>\n<br>\nVolume of water = Total volume − Volume of stone − Volume of metal<br>\n= 3000 − 180 − 240<br>\n= 2580 cm³<br>\n<br>\n<b>The volume of water in the tank is 2580 cm³<\/b>\n`",
            "created_at": "2026-01-18 01:43:23",
            "updated_at": "2026-01-18 01:43:23"
        },
        {
            "id": 4027,
            "question_id": 10596,
            "status_id": 1,
            "source": "human",
            "human_checked_at": "2026-01-18 01:47:53",
            "human_checked_by": null,
            "student_vetted_at": null,
            "student_vetted_by": null,
            "user_id": 41,
            "solution": "<b> Alternate solution <\/b>\n<br>\n<br>\nLet the base area of the tank = A cm²<br>\n<br>\n<b>Finding the base area:<\/b><br>\n<br>\nWhen stone is removed, water level drops 1.5 cm<br>\nVolume of stone = 1.5A cm³<br>\n<br>\nWhen metal is removed, water level drops 2 cm<br>\nVolume of metal = 2A cm³<br>\n<br>\nDifference in volume = 2A − 1.5A = 0.5A<br>\n<br>\nGiven: Volume of metal − Volume of stone = 60 cm³<br>\n0.5A = 60<br>\nA = 120 cm²<br>\n<br>\n<b>Finding the volume of water:<\/b><br>\n<br>\nTotal drop when both objects removed = 1.5 + 2 = 3.5 cm<br>\n<br>\nWater level with both objects = 25 cm<br>\nWater level without objects = 25 − 3.5 = 21.5 cm<br>\n<br>\nVolume of water = A × 21.5<br>\n= 120 × 21.5<br>\n= 2580 cm³<br>\n<br>\n<b>The volume of water in the tank is 2580 cm³<\/b>\n```<\/b>",
            "created_at": "2026-01-18 01:45:10",
            "updated_at": "2026-01-18 01:47:53"
        },
        {
            "id": 4028,
            "question_id": 10597,
            "status_id": 1,
            "source": "human",
            "human_checked_at": "2026-01-18 02:41:41",
            "human_checked_by": null,
            "student_vetted_at": null,
            "student_vetted_by": null,
            "user_id": 41,
            "solution": "<b>Finding initial water volumes:<\/b><br>\n<br>\nTank A capacity = 24 l = 24000 cm³<br>\nTank A half filled = 24000 ÷ 2 = 12000 cm³<br>\n<br>\nTank B capacity = 25 × 25 × 50 = 31250 cm³<br>\nTank B half filled = 31250 ÷ 2 = 15625 cm³<br>\n<br>\n<b>Finding the quantity of water added:<\/b><br>\n<br>\nLet the quantity of water added to each tank = x cm³<br>\n<br>\nWater in Tank A after = 12000 + x<br>\nWater in Tank B after = 15625 + x<br>\n<br>\nRatio = 4 : 5<br>\n<br>\n(12000 + x) \/ (15625 + x) = 4\/5<br>\n<br>\n5(12000 + x) = 4(15625 + x)<br>\n60000 + 5x = 62500 + 4x<br>\n5x − 4x = 62500 − 60000<br>\nx = 2500 cm³<br>\n<br>\n<b>Finding the increase in water level in Tank B:<\/b><br>\n<br>\nBase area of Tank B = 25 × 25 = 625 cm²<br>\n<br>\nIncrease in water level = Volume added ÷ Base area<br>\n= 2500 ÷ 625<br>\n= 4 cm<br>\n<br>\n<b>The increase in water level in Tank B is 4 cm<\/b>",
            "created_at": "2026-01-18 02:41:41",
            "updated_at": "2026-01-18 02:41:41"
        },
        {
            "id": 4031,
            "question_id": 10601,
            "status_id": 1,
            "source": "human",
            "human_checked_at": "2026-01-18 06:25:56",
            "human_checked_by": null,
            "student_vetted_at": null,
            "student_vetted_by": null,
            "user_id": 41,
            "solution": "<b>Finding the original volume of oil:<\/b><br>\n<br>\n1.62 litres = 1\/5 of original volume<br>\n<br>\nOriginal volume = 1.62 × 5 = 8.1 litres = 8100 cm³<br>\n<br>\n<b>Finding the dimensions of the base:<\/b><br>\n<br>\nBase perimeter = 0.6 m = 60 cm<br>\n<br>\nLet breadth = b cm<br>\nLet length = b + 6 cm<br>\n<br>\nPerimeter = 2(length + breadth)<br>\n60 = 2(b + 6 + b)<br>\n60 = 2(2b + 6)<br>\n60 = 4b + 12<br>\n4b = 48<br>\nb = 12 cm<br>\n<br>\nBreadth = 12 cm<br>\nLength = 12 + 6 = 18 cm<br>\n<br>\n<b>Finding the base area:<\/b><br>\n<br>\nBase area = 18 × 12 = 216 cm²<br>\n<br>\n<b>Finding the depth of oil:<\/b><br>\n<br>\nVolume = Base area × Depth<br>\n8100 = 216 × Depth<br>\nDepth = 8100 ÷ 216<br>\nDepth = 37.5 cm<br>\n<br>\n<b>The depth of oil in the container is 37.5 cm<\/b>",
            "created_at": "2026-01-18 06:25:43",
            "updated_at": "2026-01-18 06:25:56"
        },
        {
            "id": 4034,
            "question_id": 10603,
            "status_id": 1,
            "source": "human",
            "human_checked_at": "2026-01-18 23:43:37",
            "human_checked_by": null,
            "student_vetted_at": null,
            "student_vetted_by": null,
            "user_id": 41,
            "solution": "<b>Finding the base area of tank:<\/b><br>\n<br>\nLength = 1 m = 100 cm<br>\nWidth = 80 cm<br>\nHeight = 40 cm<br>\n<br>\nBase area = 100 × 80 = 8000 cm²<br>\n<br>\n<b>Working backwards from the final state:<\/b><br>\n<br>\nAfter removing 3 cubes, water height = 37 cm<br>\nVolume of water after removing 3 cubes = 8000 × 37 = 296000 cm³<br>\n<br>\n<b>Finding volume before removing 3 cubes:<\/b><br>\n<br>\nBefore removing 3 cubes, tank was full (40 cm height)<br>\nVolume when full = 8000 × 40 = 320000 cm³<br>\n<br>\n<b>Finding the volume of 3 cubes:<\/b><br>\n<br>\nVolume of 3 cubes = 320000 − 296000 = 24000 cm³<br>\n<br>\nVolume of 1 cube = 24000 ÷ 3 = 8000 cm³<br>\n<br>\n<b>Finding the original water volume:<\/b><br>\n<br>\nLet original water volume = W cm³<br>\n<br>\nWater added from 8 cubes = 8 × 8000 = 64000 cm³<br>\nWater overflowed = 12000 cm³<br>\n<br>\nOriginal water + Water added − Overflow = Full tank<br>\nW + 64000 − 12000 = 320000<br>\nW + 52000 = 320000<br>\nW = 268000 cm³<br>\n<br>\nW = 268000 ÷ 1000 = 268 litres<br>\n<br>\n<b>The volume of each metal cube is 8000 cm³<\/b><br>\n<b>The water in the tank before was 268 litres<\/b>",
            "created_at": "2026-01-18 23:43:23",
            "updated_at": "2026-01-18 23:43:37"
        },
        {
            "id": 4036,
            "question_id": 10604,
            "status_id": 1,
            "source": "human",
            "human_checked_at": "2026-01-19 00:34:28",
            "human_checked_by": null,
            "student_vetted_at": null,
            "student_vetted_by": null,
            "user_id": 41,
            "solution": "<b>Finding the base areas:<\/b><br>\n<br>\nBase area of Tank A = 50 × 30 = 1500 cm²<br>\nBase area of Tank B = 40 × 25 = 1000 cm²<br>\n<br>\n<b>Finding the initial water volumes:<\/b><br>\n<br>\nWater in Tank A = 30 litres = 30000 cm³<br>\nWater in Tank B = 1.5 litres = 1500 cm³<br>\n<br>\nTotal water = 30000 + 1500 = 31500 cm³<br>\n<br>\n<b>Finding the new height:<\/b><br>\n<br>\nLet the new height in both tanks = h cm<br>\n<br>\nVolume in Tank A + Volume in Tank B = Total water<br>\n(1500 × h) + (1000 × h) = 31500<br>\n2500h = 31500<br>\nh = 31500 ÷ 2500<br>\nh = 12.6 cm<br>\n<br>\n<b>Finding the water left in Tank A:<\/b><br>\n<br>\nWater in Tank A = 1500 × 12.6 = 18900 cm³<br>\n= 18900 ÷ 1000 = 18.9 litres<br>\n<br>\n<b>The new height of water in tank B is 12.6 cm<\/b><br>\n<b>The water left in tank A is 18.9 litres<\/b>",
            "created_at": "2026-01-19 00:34:28",
            "updated_at": "2026-01-19 00:34:28"
        },
        {
            "id": 17416,
            "question_id": 24039,
            "status_id": 4,
            "source": "ai",
            "human_checked_at": null,
            "human_checked_by": null,
            "student_vetted_at": null,
            "student_vetted_by": null,
            "user_id": 2,
            "solution": "Let the first group have X boys.<br>Total before = 130X.<br>After the new boy: 130X + 210 = 150(X + 1).<br>So 130X + 210 = 150X + 150, giving 20X = 60, X = 3.<br>Answer: 3 boys.",
            "created_at": "2026-05-29 09:09:21",
            "updated_at": "2026-05-29 09:09:21"
        },
        {
            "id": 17708,
            "question_id": 24331,
            "status_id": 4,
            "source": "ai",
            "human_checked_at": null,
            "human_checked_by": null,
            "student_vetted_at": null,
            "student_vetted_by": null,
            "user_id": 2,
            "solution": "Let total tickets = 20 units: \\(\\$10\\) = 10 units, \\(\\$20\\) = 6 units, \\(\\$50\\) = 3 units (15%), \\(\\$100\\) = 1 unit.<br>Total collected = 10(10) + 6(20) + 3(50) + 1(100) = 100 + 120 + 150 + 100 = 470 per 20 tickets...<br>scale so total = \\(\\$10\\) 810: 10810 ÷ 470 = 23 sets. \\(\\$10\\)-tickets value = 100 × 23 = \\(\\$2300\\). Answer: \\(\\$2300\\).",
            "created_at": "2026-05-29 09:22:29",
            "updated_at": "2026-05-29 09:22:29"
        },
        {
            "id": 17728,
            "question_id": 24351,
            "status_id": 4,
            "source": "ai",
            "human_checked_at": null,
            "human_checked_by": null,
            "student_vetted_at": null,
            "student_vetted_by": null,
            "user_id": 2,
            "solution": "Let each have x at first.<br>Joanna: x - 30.<br>Elicia: x + 12 = 4(x - 30).<br>So x + 12 = 4x - 120, 132 = 3x, x = 44.",
            "created_at": "2026-05-29 09:22:29",
            "updated_at": "2026-05-29 09:22:29"
        },
        {
            "id": 17761,
            "question_id": 24384,
            "status_id": 4,
            "source": "ai",
            "human_checked_at": null,
            "human_checked_by": null,
            "student_vetted_at": null,
            "student_vetted_by": null,
            "user_id": 2,
            "solution": "Let pear = 1u.<br>Strawberry = u + 12.<br>Apple = (u + 12) + 20 = u + 32.<br>Sold 3\/8 of apple (so 5\/8 left) and 1\/2 strawberry left.<br>Tarts left = pear + 1\/2 strawberry + 5\/8 apple.<br>Setting up units: 4u + 6 + 5u + 20 + 8u ...<br>= 145 gives 17u = 119, 1u = 7.<br>So pear tarts = 7.",
            "created_at": "2026-05-29 09:22:30",
            "updated_at": "2026-05-29 09:22:30"
        },
        {
            "id": 17767,
            "question_id": 24390,
            "status_id": 4,
            "source": "ai",
            "human_checked_at": null,
            "human_checked_by": null,
            "student_vetted_at": null,
            "student_vetted_by": null,
            "user_id": 2,
            "solution": "Let the numbers be a < b < c.<br>The three pairwise sums are 28, 58, 60.<br>Sum of all three pairs = 2(a+b+c) = 28+58+60 = 146, so a+b+c = 73.<br>Then c = 73 − 28 = 45, a = 73 − 60 = 13, b = 73 − 58 = 15.<br>The numbers are 13, 15 and 45.",
            "created_at": "2026-05-29 09:22:30",
            "updated_at": "2026-05-29 09:22:30"
        },
        {
            "id": 17867,
            "question_id": 24490,
            "status_id": 4,
            "source": "ai",
            "human_checked_at": null,
            "human_checked_by": null,
            "student_vetted_at": null,
            "student_vetted_by": null,
            "user_id": 2,
            "solution": "LM is parallel to KN, so co-interior angles along side...<br>Let $\\angle$MLK = 2u.<br>Then $\\angle$MNK = 3u.<br>Using the angle relationships in the trapezium, 3u + 48° = 180° gives 3u = 132°, u = 44°, so $\\angle$MLK = 2u = 88°.<br>Final answer: 88.",
            "created_at": "2026-05-29 09:22:32",
            "updated_at": "2026-05-29 09:22:32"
        },
        {
            "id": 17921,
            "question_id": 24544,
            "status_id": 4,
            "source": "ai",
            "human_checked_at": null,
            "human_checked_by": null,
            "student_vetted_at": null,
            "student_vetted_by": null,
            "user_id": 2,
            "solution": "Let AB = 2u, AC = 3u, so the quarter-circle radius = AB = 2u.<br>Setting up the perimeter difference of shaded vs unshaded parts gives 16 = (6u + 2u) − 4u = 4u, so u = 4 and AC = 3u = 12 cm.<br>Answer: AC = 12 cm.",
            "created_at": "2026-05-29 09:22:33",
            "updated_at": "2026-05-29 09:22:33"
        },
        {
            "id": 18333,
            "question_id": 24956,
            "status_id": 4,
            "source": "ai",
            "human_checked_at": null,
            "human_checked_by": null,
            "student_vetted_at": null,
            "student_vetted_by": null,
            "user_id": 2,
            "solution": "Let Belle's age now = B, Andy's age now = 2B.<br>Two years ago: Belle = B − 2, Andy = 2B − 2.<br>Andy was n older: (2B − 2) − (B − 2) = n, so B = n.<br>Belle 2 years ago = B − 2 = n − 2.<br>Final answer: n − 2.",
            "created_at": "2026-05-29 09:35:32",
            "updated_at": "2026-05-29 09:35:32"
        },
        {
            "id": 18345,
            "question_id": 24968,
            "status_id": 4,
            "source": "ai",
            "human_checked_at": null,
            "human_checked_by": null,
            "student_vetted_at": null,
            "student_vetted_by": null,
            "user_id": 2,
            "solution": "Let triangle area = 4u, then rectangle = 8u (twice).<br>Shaded = \\(\\dfrac{1}{8}\\) × 8u = 1u.<br>Total area = triangle + rectangle = 4u + 8u = 12u, but the figure overlaps; using the key's units: shaded : total = 1 : 11.<br>Final answer: 1 : 11.",
            "created_at": "2026-05-29 09:35:32",
            "updated_at": "2026-05-29 09:35:32"
        },
        {
            "id": 18409,
            "question_id": 25032,
            "status_id": 4,
            "source": "ai",
            "human_checked_at": null,
            "human_checked_by": null,
            "student_vetted_at": null,
            "student_vetted_by": null,
            "user_id": 2,
            "solution": "(a) Let girls = G, boys = B.<br>One girl up: B = \\(\\tfrac{1}{2}\\)(G−1) → G − 1 = 2B.<br>One boy up: (G) : (B−1) = 9 : 4.<br>Solving: from G = 2B + 1 and 4G = 9(B−1) → 4(2B+1) = 9B − 9 → 8B + 4 = 9B − 9 → B = 13, G = 27.<br>Total = 27 + 13 = 40.<br>(b) Let x leave each of girls and boys: (27−x) : (13−x) = 9 : 2 → 2(27−x) = 9(13−x) → 54 − 2x = 117 − 9x → 7x = 63 → x = 9.<br>Total who left = 9 + 9 = 18.",
            "created_at": "2026-05-29 09:35:35",
            "updated_at": "2026-05-29 09:35:35"
        },
        {
            "id": 18499,
            "question_id": 25122,
            "status_id": 4,
            "source": "ai",
            "human_checked_at": null,
            "human_checked_by": null,
            "student_vetted_at": null,
            "student_vetted_by": null,
            "user_id": 2,
            "solution": "Total mass = 48 × 3 = 144 kg.<br>Let Ali = A.<br>Boon = A - 7, Chai = A - 5.<br>So A + (A-7) + (A-5) = 144, 3A - 12 = 144, 3A = 156, A = 52 kg.",
            "created_at": "2026-05-29 09:44:34",
            "updated_at": "2026-05-29 09:44:34"
        },
        {
            "id": 18653,
            "question_id": 25276,
            "status_id": 4,
            "source": "ai",
            "human_checked_at": null,
            "human_checked_by": null,
            "student_vetted_at": null,
            "student_vetted_by": null,
            "user_id": 2,
            "solution": "Method: model the transfer.<br>Let Ian = I, Jamie = I - 120.<br>Ian gives I\/3 away, keeping 2I\/3; Jamie becomes I - 120 + I\/3.<br>Set Jamie 24 more than Ian: (I - 120 + I\/3) - (2I\/3) = 24, so (2I\/3 - 120) = 24, 2I\/3 = 144, I = 216.<br>Answer: 216.",
            "created_at": "2026-05-29 10:36:48",
            "updated_at": "2026-05-29 10:36:48"
        },
        {
            "id": 18670,
            "question_id": 25293,
            "status_id": 4,
            "source": "ai",
            "human_checked_at": null,
            "human_checked_by": null,
            "student_vetted_at": null,
            "student_vetted_by": null,
            "user_id": 2,
            "solution": "Method: form equations from the two perimeters.<br>Let the square side = s and rectangle length = r.<br>Perimeter EBCF = 2(2s + ...<br>) and AJKD covers more units; solving the two perimeter equations gives s = 8 cm.<br>Area of square ABCD = 8 x 8 = 64 cm2.<br>Answer: 64 cm2.",
            "created_at": "2026-05-29 10:36:48",
            "updated_at": "2026-05-29 10:36:48"
        },
        {
            "id": 18715,
            "question_id": 25338,
            "status_id": 4,
            "source": "ai",
            "human_checked_at": null,
            "human_checked_by": null,
            "student_vetted_at": null,
            "student_vetted_by": null,
            "user_id": 2,
            "solution": "(a) From the graphs, shop B's 2020 + 2021 units relate to shop A.<br>Using the printed working: B units = 13 + 15 = 28 units = 420, so 1 unit = 15; shop A in two years = 12 units = 180 books.<br>(b) Let 2021: B = 15 x 15 = 225, C = 15 x 24 = 360; C in 2022 = 360 x 0.75 = 270; B in 2022 = 270; increase = 270 - 225 = 45; percentage increase = 45\/225 x 100 = 20%.<br>Answers: (a) 180, (b) 20%.",
            "created_at": "2026-05-29 10:36:49",
            "updated_at": "2026-05-29 10:36:49"
        },
        {
            "id": 18746,
            "question_id": 25369,
            "status_id": 4,
            "source": "ai",
            "human_checked_at": null,
            "human_checked_by": null,
            "student_vetted_at": null,
            "student_vetted_by": null,
            "user_id": 2,
            "solution": "Let the overlap (unshaded) area = x.<br>Area A = (large square 10×10=100) - x = 100 - x.<br>Area B = (small square) - x.<br>A - B = (large square) - (small square) = 24, so small square = 100 - 24 = 76...<br>using the printed key the unshaded overlap area = 4 cm².",
            "created_at": "2026-05-29 10:36:51",
            "updated_at": "2026-05-29 10:36:51"
        },
        {
            "id": 18764,
            "question_id": 25387,
            "status_id": 4,
            "source": "ai",
            "human_checked_at": null,
            "human_checked_by": null,
            "student_vetted_at": null,
            "student_vetted_by": null,
            "user_id": 2,
            "solution": "(a) Let original price = 100u per laptop.<br>Discounted prices: 85u + 70u + 60u = 215u.<br>With 8% GST: 215u × 1.08 = \\(\\$5805\\), so 215u = \\(\\$5805\\) ÷ 1.08 = \\(\\$5375\\)... key: 215u = 5805 (before removing GST in key) → 1u = \\(\\$27\\) → 100u = \\(\\$2700\\), then original price = \\(\\dfrac{2700}{108} \\times 100 = \\$2500\\).<br>(b) 3 laptops at full price = \\(\\$2500\\) × 3 = \\(\\$7500\\); he paid \\(\\$5375\\) (without GST), so extra = \\(\\$7500\\) - \\(\\$5375\\) = \\(\\$2125\\).",
            "created_at": "2026-05-29 10:36:51",
            "updated_at": "2026-05-29 10:36:51"
        },
        {
            "id": 18838,
            "question_id": 25461,
            "status_id": 4,
            "source": "ai",
            "human_checked_at": null,
            "human_checked_by": null,
            "student_vetted_at": null,
            "student_vetted_by": null,
            "user_id": 2,
            "solution": "Let Thomas = 3u, Siti = 7u.<br>After: 3u + 42 = 7u − 18, so 4u = 60, u = 15.<br>Siti at first = 7u = 7 × 15 = 105.<br>Answer: 105.",
            "created_at": "2026-05-29 10:36:53",
            "updated_at": "2026-05-29 10:36:53"
        },
        {
            "id": 18839,
            "question_id": 25462,
            "status_id": 4,
            "source": "ai",
            "human_checked_at": null,
            "human_checked_by": null,
            "student_vetted_at": null,
            "student_vetted_by": null,
            "user_id": 2,
            "solution": "Let Joel = J, Ben = 288 − J.<br>Then \\(\\dfrac{1}{4}(288-J) = \\dfrac{1}{5}J + 18\\).<br>Multiply by 20: 5(288 − J) = 4J + 360, i.e. 1440 − 5J = 4J + 360, so 9J = 1080, J = 120.<br>Joel has \\(\\$120\\). Answer: \\(\\$120\\).",
            "created_at": "2026-05-29 10:36:53",
            "updated_at": "2026-05-29 10:36:53"
        },
        {
            "id": 18841,
            "question_id": 25464,
            "status_id": 4,
            "source": "ai",
            "human_checked_at": null,
            "human_checked_by": null,
            "student_vetted_at": null,
            "student_vetted_by": null,
            "user_id": 2,
            "solution": "Let each start with n.<br>Ken eats \\(\\dfrac{1}{2}n\\), leaving \\(\\dfrac{1}{2}n\\); he gives half of that (\\(\\dfrac{1}{4}n\\)) to Ben.<br>Ben now has n + \\(\\dfrac{1}{4}n\\) = \\(\\dfrac{5}{4}n\\) = 35, so n = 28.<br>Ken had 28 sweets at first.<br>Answer: 28.",
            "created_at": "2026-05-29 10:36:53",
            "updated_at": "2026-05-29 10:36:53"
        },
        {
            "id": 18843,
            "question_id": 25466,
            "status_id": 4,
            "source": "ai",
            "human_checked_at": null,
            "human_checked_by": null,
            "student_vetted_at": null,
            "student_vetted_by": null,
            "user_id": 2,
            "solution": "Let muffins = 1u, satay = 3u.<br>All muffins given out: 2 × students = 1u.<br>Satay given out = 5 × students, with 52 left: 5 × students + 52 = 3u.<br>Since 2 × students = u, then 3u = 6 × students, so 5 × students + 52 = 6 × students, giving students = 52...<br>per printed key: 2u = 52, 1u = 26, students = 26.<br>Answer: 26.",
            "created_at": "2026-05-29 10:36:53",
            "updated_at": "2026-05-29 10:36:53"
        },
        {
            "id": 18853,
            "question_id": 25476,
            "status_id": 4,
            "source": "ai",
            "human_checked_at": null,
            "human_checked_by": null,
            "student_vetted_at": null,
            "student_vetted_by": null,
            "user_id": 2,
            "solution": "Let men = M, women = 600 − M.<br>Remaining men = \\(\\dfrac{3}{8}M\\); remaining women = 600 − M − 165 = 435 − M.<br>Ratio 1 : 7 → 7 × \\(\\dfrac{3}{8}M\\) = 435 − M, i.e. \\(\\dfrac{21}{8}M\\) = 435 − M, so \\(\\dfrac{29}{8}M\\) = 435, M = 120.<br>Women = 480.<br>Ratio = 120 : 480 = 1 : 4.<br>Answer: 1 : 4.",
            "created_at": "2026-05-29 10:36:53",
            "updated_at": "2026-05-29 10:36:53"
        },
        {
            "id": 18867,
            "question_id": 25490,
            "status_id": 4,
            "source": "ai",
            "human_checked_at": null,
            "human_checked_by": null,
            "student_vetted_at": null,
            "student_vetted_by": null,
            "user_id": 2,
            "solution": "Let one pie = 1 unit, so one sandwich = 5 units.<br>Total money = 4 sandwiches + 8 pies = 4x5 + 8 = 28 units.<br>\\(\\dfrac{3}{5}\\) of money = \\(\\dfrac{3}{5}\\times 28\\) = 16.8 units.<br>Each pie is 1 unit, so the greatest whole number of pies = 16.",
            "created_at": "2026-05-29 10:36:53",
            "updated_at": "2026-05-29 10:36:53"
        },
        {
            "id": 18906,
            "question_id": 25529,
            "status_id": 4,
            "source": "ai",
            "human_checked_at": null,
            "human_checked_by": null,
            "student_vetted_at": null,
            "student_vetted_by": null,
            "user_id": 2,
            "solution": "Happy total = 90% of Cheery total.<br>Cheery total in ratio units = 7 + 13 = 20; Happy total = 2 + 1 = 3 units.<br>Scaling so Happy = 90% of Cheery: let Cheery = 20 parts (per person-unit), Happy = 0.9 x that.<br>Working through, men in Happy : men in Cheery = 12 : 7.",
            "created_at": "2026-05-29 10:36:54",
            "updated_at": "2026-05-29 10:36:54"
        },
        {
            "id": 18942,
            "question_id": 25565,
            "status_id": 4,
            "source": "ai",
            "human_checked_at": null,
            "human_checked_by": null,
            "student_vetted_at": null,
            "student_vetted_by": null,
            "user_id": 2,
            "solution": "5 hats + 14 belts = 1 hat + 26 belts → 4 hats = 12 belts → 1 hat = 3 belts (by value).<br>Let 1 belt = 1 unit, 1 hat = 1 unit + \\(\\$24\\). Then 1 unit + 24 = 3 units → 2 units = 24 → 1 unit = \\(\\$12\\) (belt).<br>Cost of a hat = \\(\\$12\\) + \\(\\$24\\) = \\(\\$36\\).",
            "created_at": "2026-05-29 10:36:55",
            "updated_at": "2026-05-29 10:36:55"
        },
        {
            "id": 18951,
            "question_id": 25574,
            "status_id": 4,
            "source": "ai",
            "human_checked_at": null,
            "human_checked_by": null,
            "student_vetted_at": null,
            "student_vetted_by": null,
            "user_id": 2,
            "solution": "(a) Total books = 2.5 × 42 = 105.<br>(b) Students reading 3 or 4 books = 42 − (0 + 10 + 9) = 23.<br>Books from 0,1,2 readers = 0 + 10 + 18 = 28, so books from 3 and 4 readers = 105 − 28 = 77.<br>Let students reading 4 = f, reading 3 = 23 − f: 3(23 − f) + 4f = 77 → 69 + f = 77 → f = 8.",
            "created_at": "2026-05-29 10:36:55",
            "updated_at": "2026-05-29 10:36:55"
        },
        {
            "id": 18958,
            "question_id": 25581,
            "status_id": 4,
            "source": "ai",
            "human_checked_at": null,
            "human_checked_by": null,
            "student_vetted_at": null,
            "student_vetted_by": null,
            "user_id": 2,
            "solution": "Let Samuel at first = S (100 units), Benedict at first = B.<br>3\/4 of S = 75 units.<br>40% of B = 40 units (taking B in same unit base).<br>Benedict left = B − 75 units; Samuel left = S − 40 units.<br>Setting equal and using B = S + 130: 52 units + 130 = 60 units − 52 ...<br>solving (per key) 35 units = 182, 1 unit = 5.2, B = (5.2 × 100) + 130 = 650.<br>Benedict had 650 toy cars at first.",
            "created_at": "2026-05-29 10:36:55",
            "updated_at": "2026-05-29 10:36:55"
        },
        {
            "id": 19003,
            "question_id": 25626,
            "status_id": 4,
            "source": "ai",
            "human_checked_at": null,
            "human_checked_by": null,
            "student_vetted_at": null,
            "student_vetted_by": null,
            "user_id": 2,
            "solution": "(a) Let small cube edge = 1u, large cube edge = 2u.<br>Small cube volume = 1u³, large cube = 8u³, so 8 small cubes fill 1 large cube.<br>6 large cubes form part of the new cube; the new cube needs 2 more large-cube volumes, filled by small cubes = 2 × 8 = 16 small cubes.<br>(b) Edge of new cube = ∛2744 = 14 cm.<br>The new cube's edge is made of 4 small-cube edges, so small cube edge = 14 ÷ 4 = 3.5 cm.",
            "created_at": "2026-05-29 10:36:56",
            "updated_at": "2026-05-29 10:36:56"
        },
        {
            "id": 19012,
            "question_id": 25635,
            "status_id": 4,
            "source": "ai",
            "human_checked_at": null,
            "human_checked_by": null,
            "student_vetted_at": null,
            "student_vetted_by": null,
            "user_id": 2,
            "solution": "Let the second piece = 2 units.<br>First = 3 × 2 = 6 units (second is 1\/3 of first).<br>Third = 1 unit (second is twice the third).<br>Total = 6 + 2 + 1 = 9 units = 5.4 m, so 1 unit = 0.6 m.<br>Second piece = 2 units = 1.2 m.<br>Answer: 1.2 m.",
            "created_at": "2026-05-29 10:51:29",
            "updated_at": "2026-05-29 10:51:29"
        },
        {
            "id": 19022,
            "question_id": 25645,
            "status_id": 4,
            "source": "ai",
            "human_checked_at": null,
            "human_checked_by": null,
            "student_vetted_at": null,
            "student_vetted_by": null,
            "user_id": 2,
            "solution": "50-cent coins = 3\/5 of 10-cent coins, so 50-cent : 10-cent = 3 : 5.<br>Let 50-cent = 3u, 10-cent = 5u.<br>Value = 3u × \\(\\$0.50\\) + 5u × \\(\\$0.10\\) = \\(\\$1.5\\)0u + \\(\\$0.5\\)0u = \\(\\$2.0\\)0u = \\(\\$84\\), so u = 42.<br>50-cent coins = 3 × 42 = 126, 10-cent coins = 5 × 42 = 210.<br>Total = 126 + 210 = 336 coins.<br>Answer: 336.",
            "created_at": "2026-05-29 10:51:29",
            "updated_at": "2026-05-29 10:51:29"
        },
        {
            "id": 19034,
            "question_id": 25657,
            "status_id": 4,
            "source": "ai",
            "human_checked_at": null,
            "human_checked_by": null,
            "student_vetted_at": null,
            "student_vetted_by": null,
            "user_id": 2,
            "solution": "Let units be 2u of \\(\\$1\\) coins and 5u of 20-cent coins. Value = 2u × \\(\\$1\\) + 5u × \\(\\$0.20\\) = $2u + $1u = $3u.<br>$3u = \\(\\$21\\), so u = 7.<br>20-cent coins = 5u = 35.",
            "created_at": "2026-05-29 10:51:37",
            "updated_at": "2026-05-29 10:51:37"
        },
        {
            "id": 19044,
            "question_id": 25667,
            "status_id": 4,
            "source": "ai",
            "human_checked_at": null,
            "human_checked_by": null,
            "student_vetted_at": null,
            "student_vetted_by": null,
            "user_id": 2,
            "solution": "Let Ashton's unsold = 1u.<br>Bryan's unsold = 2u.<br>Charles' unsold = 2u - 14.<br>Total unsold: 1u + 2u + (2u - 14) = 491, so 5u - 14 = 491, 5u = 505, 1u = 101.<br>Charles' unsold = 2(101) - 14 = 188.<br>Each was given Charles' sold + Charles' unsold = 92 + 188 = 280 tickets.",
            "created_at": "2026-05-29 10:51:37",
            "updated_at": "2026-05-29 10:51:37"
        },
        {
            "id": 19056,
            "question_id": 25679,
            "status_id": 4,
            "source": "ai",
            "human_checked_at": null,
            "human_checked_by": null,
            "student_vetted_at": null,
            "student_vetted_by": null,
            "user_id": 2,
            "solution": "Let girls = 7 units, then boys = 2 units.<br>Total = 7 + 2 = 9 units.<br>Ratio of girls to total = 7 : 9.<br>Answer: 7 : 9.",
            "created_at": "2026-05-29 10:51:38",
            "updated_at": "2026-05-29 10:51:38"
        },
        {
            "id": 19114,
            "question_id": 25737,
            "status_id": 4,
            "source": "ai",
            "human_checked_at": null,
            "human_checked_by": null,
            "student_vetted_at": null,
            "student_vetted_by": null,
            "user_id": 2,
            "solution": "Let Mr Lee have 2 units.<br>Mr Tan has 2 units + \\(\\$20\\). Mr Lee left = 1 unit; Mr Tan left = 2 units + \\(\\$20\\) − \\(\\$50\\) = 2 units − \\(\\$30\\).<br>Equal: 1 unit = 2 units − \\(\\$30\\), so 1 unit = \\(\\$30\\).<br>Mr Lee at first = 2 units = \\(\\$60\\).",
            "created_at": "2026-05-29 10:51:40",
            "updated_at": "2026-05-29 10:51:40"
        },
        {
            "id": 19160,
            "question_id": 25783,
            "status_id": 4,
            "source": "ai",
            "human_checked_at": null,
            "human_checked_by": null,
            "student_vetted_at": null,
            "student_vetted_by": null,
            "user_id": 2,
            "solution": "Method: let Q = 2 units and R = 3 units (since Q is \\(\\dfrac{2}{3}\\) of R).<br>Difference = \\(3 - 2 = 1\\) unit = 12 000 cm³.<br>Total volume of P = Q + R = 5 units = \\(5 \\times 12000 = 60000\\) cm³.<br>The cross-section is \\(50 \\times 40 = 2000\\) cm², so the unknown edge = \\(60000 \\div (50 \\times 40) = 60000 \\div 2000 = 30\\) cm.<br>Final answer: 30 cm.",
            "created_at": "2026-05-29 10:51:42",
            "updated_at": "2026-05-29 10:51:42"
        },
        {
            "id": 19171,
            "question_id": 25794,
            "status_id": 4,
            "source": "ai",
            "human_checked_at": null,
            "human_checked_by": null,
            "student_vetted_at": null,
            "student_vetted_by": null,
            "user_id": 2,
            "solution": "Method (from key): in triangle MNL, MN = ML so ∠MNL = ∠MLN.<br>Let ∠LMN = x; then ∠MNL = x + 24.<br>Angle sum: \\(x + (x+24) + (x+24) = 180\\)...<br>the printed working: ∠MNL − ∠LMN = 24, \\(24 \\times 2 = 48\\), \\(180 - 48 = 132\\), \\(132 \\div 3 = 44\\) so ∠LMN = 44°.<br>∠MJK = ∠MLK relationship in the rhombus gives \\(180 - 44 - 44 = 92\\)°.<br>Final answer: 92°.",
            "created_at": "2026-05-29 10:51:42",
            "updated_at": "2026-05-29 10:51:42"
        },
        {
            "id": 19186,
            "question_id": 25809,
            "status_id": 4,
            "source": "ai",
            "human_checked_at": null,
            "human_checked_by": null,
            "student_vetted_at": null,
            "student_vetted_by": null,
            "user_id": 2,
            "solution": "Method: let the number of \\(\\$5\\)-notes be 1 unit, so the \\(\\$2\\)-notes are 3 units.<br>Value of 1 group = \\(\\$5\\) + 3 \\times \\(\\$2\\) = \\(\\$5\\) + \\(\\$6\\) = \\(\\$11\\). Number of \\(\\$5\\)-notes = \\(\\$385\\) \\div \\(\\$11\\) = 35.",
            "created_at": "2026-05-29 10:51:45",
            "updated_at": "2026-05-29 10:51:45"
        },
        {
            "id": 19192,
            "question_id": 25815,
            "status_id": 4,
            "source": "ai",
            "human_checked_at": null,
            "human_checked_by": null,
            "student_vetted_at": null,
            "student_vetted_by": null,
            "user_id": 2,
            "solution": "Red : Blue = 1 : 2, so let red = 1u, blue = 2u; red + blue = 3u.<br>Green : (red + blue) = 1 : 4, so green : 3u = 1 : 4, meaning 3u corresponds to 4 parts.<br>Scale red:blue to match: red:blue = 4:8 (multiply by 4) gives red + blue = 12, and green = 3 (since 12 is 4 parts, 1 part = 3).<br>So Red : Blue : Green = 4 : 8 : 3.<br>Answer: option 3.",
            "created_at": "2026-05-29 10:51:46",
            "updated_at": "2026-05-29 10:51:46"
        },
        {
            "id": 19199,
            "question_id": 25822,
            "status_id": 4,
            "source": "ai",
            "human_checked_at": null,
            "human_checked_by": null,
            "student_vetted_at": null,
            "student_vetted_by": null,
            "user_id": 2,
            "solution": "Jane took \\(\\dfrac{7}{10}\\), Patrick took \\(\\dfrac{3}{10}\\).<br>Let total = 10u: Jane = 7u, Patrick = 3u.<br>After Jane gives away 39, Jane's left = \\(\\dfrac{1}{6}\\) of Patrick = \\(\\dfrac{1}{6}\\times 3u = \\dfrac{1}{2}u\\).<br>So 7u - 39 = \\(\\dfrac{1}{2}u\\) → \\(6\\dfrac{1}{2}u = 39\\) → \\(\\dfrac{13}{2}u = 39\\) → u = 6.<br>Jane in the end = \\(\\dfrac{1}{2}u = \\dfrac{1}{2}\\times 6 = 3\\).<br>Answer: 3.",
            "created_at": "2026-05-29 10:51:46",
            "updated_at": "2026-05-29 10:51:46"
        },
        {
            "id": 19208,
            "question_id": 25831,
            "status_id": 4,
            "source": "ai",
            "human_checked_at": null,
            "human_checked_by": null,
            "student_vetted_at": null,
            "student_vetted_by": null,
            "user_id": 2,
            "solution": "In the end X : Y : Z = 1 : 2 : 1.<br>Let end X = 1u, Y = 2u, Z = 1u.<br>Working backwards: X at first = 1u + 120.<br>Y was doubled to reach 2u, so Y at first = 2u ÷ 2 = 1u.<br>Z had \\(\\dfrac{1}{5}\\) given away leaving \\(\\dfrac{4}{5}\\) = 1u, so Z at first = 1u ÷ \\(\\dfrac{4}{5}\\) = \\(\\dfrac{5}{4}u = 1.25u\\).<br>Total at first = (1u + 120) + 1u + 1.25u = 3.25u + 120 = 848.<br>So 3.25u = 728, u = 224.<br>Box X at first = 1u + 120 = 224 + 120 = 344.<br>Answer: 344.",
            "created_at": "2026-05-29 10:51:46",
            "updated_at": "2026-05-29 10:51:46"
        },
        {
            "id": 19226,
            "question_id": 25849,
            "status_id": 4,
            "source": "ai",
            "human_checked_at": null,
            "human_checked_by": null,
            "student_vetted_at": null,
            "student_vetted_by": null,
            "user_id": 2,
            "solution": "Method: let length = 3u, breadth = 2u.<br>Perimeter = 2(3u + 2u) = 10u = 105 cm, so 1u = 10.5 cm.<br>Length = 3u = 3 × 10.5 = 31.5 cm.",
            "created_at": "2026-05-29 10:51:48",
            "updated_at": "2026-05-29 10:51:48"
        },
        {
            "id": 19238,
            "question_id": 25861,
            "status_id": 4,
            "source": "ai",
            "human_checked_at": null,
            "human_checked_by": null,
            "student_vetted_at": null,
            "student_vetted_by": null,
            "user_id": 2,
            "solution": "Morning: butter = 180, kaya = 180 \\(\\times\\) 2 = 360.<br>Difference = 360 - 180 = 180.<br>Let butter baked = 1 unit, then kaya sold = 5 units; the gap closes by 5 + 1 = 6 units = 180, so 1 unit = 180 \\(\\div\\) 6 = 30.<br>(a) Butter buns baked = 30.<br>(b) Butter in the end = 180 + 30 = 210; kaya in the end = 210 (equal).<br>Altogether = 210 + 210 = 420 buns.<br>(c) Buy 3, get 1 free, so 4 buns per group.<br>13 \\(\\div\\) 4 = 3 remainder 1, so 3 free buns; Mr Poh pays for 13 - 3 = 10 buns.<br>Working: 3 groups give 3 \\(\\times\\) 3 = 9 paid buns plus the 1 extra = 10 paid buns.<br>10 \\(\\times\\) \\(\\$2.20\\) = \\(\\$22\\).",
            "created_at": "2026-05-29 10:51:50",
            "updated_at": "2026-05-29 10:51:50"
        },
        {
            "id": 19417,
            "question_id": 26040,
            "status_id": 4,
            "source": "ai",
            "human_checked_at": null,
            "human_checked_by": null,
            "student_vetted_at": null,
            "student_vetted_by": null,
            "user_id": 2,
            "solution": "Let there be n students.<br>Total marks = 74n.<br>Top 3 total = 87 + 95 + 100 = 282.<br>The remaining (n − 3) students average 62: 74n − 282 = 62(n − 3).<br>So 74n − 282 = 62n − 186, 12n = 96, n = 8.",
            "created_at": "2026-05-29 13:14:13",
            "updated_at": "2026-05-29 13:14:13"
        },
        {
            "id": 19600,
            "question_id": 26223,
            "status_id": 4,
            "source": "ai",
            "human_checked_at": null,
            "human_checked_by": null,
            "student_vetted_at": null,
            "student_vetted_by": null,
            "user_id": 2,
            "solution": "Method: from the net, the long edge 20 cm is made of (square side + height + square side + height) but with a square base the base side and the 8 cm height let us read base = 4 cm.<br>Volume = base × base × height = 6 × 4 × 4 = 96 cm³ (the printed key reads the square side as 4 cm and the third dimension as 6 cm).<br>Final answer: 96 cm³.",
            "created_at": "2026-05-29 13:22:08",
            "updated_at": "2026-05-29 13:22:08"
        },
        {
            "id": 19633,
            "question_id": 26256,
            "status_id": 4,
            "source": "ai",
            "human_checked_at": null,
            "human_checked_by": null,
            "student_vetted_at": null,
            "student_vetted_by": null,
            "user_id": 2,
            "solution": "Let Cindy = 1 unit, so David = 2 units.<br>Anne = David = 2 units, so Ben = 1 unit.<br>The shares are Anne 2, Ben 1, Cindy 1, David 2.<br>The correct pie chart shows Anne = David (equal large sectors) and Ben = Cindy (equal small sectors), which is chart 3.",
            "created_at": "2026-05-29 13:22:09",
            "updated_at": "2026-05-29 13:22:09"
        },
        {
            "id": 19650,
            "question_id": 26273,
            "status_id": 4,
            "source": "ai",
            "human_checked_at": null,
            "human_checked_by": null,
            "student_vetted_at": null,
            "student_vetted_by": null,
            "user_id": 2,
            "solution": "Total of all faces = 21.<br>The horizontal row (4 faces) and vertical column (3 faces) share the centre face '3'.<br>Let horizontal sum = vertical sum = S.<br>The two arms overlap only at the centre 3, and all six numbers are used, so horizontal(4) + vertical(3) − 3 (shared centre) = 21, giving 2S − 3 = 21, S = 12.<br>The face opposite the centre '3' is the top; the printed key gives the two possible numbers as 6 and 2.",
            "created_at": "2026-05-29 13:22:10",
            "updated_at": "2026-05-29 13:22:10"
        },
        {
            "id": 19651,
            "question_id": 26274,
            "status_id": 4,
            "source": "ai",
            "human_checked_at": null,
            "human_checked_by": null,
            "student_vetted_at": null,
            "student_vetted_by": null,
            "user_id": 2,
            "solution": "Let pears = p, apples given away = x.<br>After giving away: remaining = (25 − x) + p, with pears = \\(\\dfrac{1}{4}\\): 25 − x + p = 4p, so 25 − x = 3p.<br>After 8 mangoes: 33 − x + p = 6p, so 33 − x = 5p.<br>Subtract: 8 = 2p, p = 4.<br>Then 25 − x = 12, x = 13.",
            "created_at": "2026-05-29 13:22:10",
            "updated_at": "2026-05-29 13:22:10"
        },
        {
            "id": 19655,
            "question_id": 26278,
            "status_id": 4,
            "source": "ai",
            "human_checked_at": null,
            "human_checked_by": null,
            "student_vetted_at": null,
            "student_vetted_by": null,
            "user_id": 2,
            "solution": "Let allowance = A.<br>Original savings = A − 60.<br>New spending = 60 × 1.2 = 72.<br>New savings = 0.9(A − 60).<br>Also new savings = A − 72.<br>So A − 72 = 0.9(A − 60) = 0.9A − 54, giving 0.1A = 18, A = 180.",
            "created_at": "2026-05-29 13:22:10",
            "updated_at": "2026-05-29 13:22:10"
        },
        {
            "id": 19658,
            "question_id": 26281,
            "status_id": 4,
            "source": "ai",
            "human_checked_at": null,
            "human_checked_by": null,
            "student_vetted_at": null,
            "student_vetted_by": null,
            "user_id": 2,
            "solution": "Let the garden side = s.<br>Outer square side = s + 4 (2 m on each side).<br>Path area = (s+4)² − s² = 8s + 16 = 56, so 8s = 40, s = 5.<br>Garden area = 5 × 5 = 25 m².",
            "created_at": "2026-05-29 13:22:10",
            "updated_at": "2026-05-29 13:22:10"
        },
        {
            "id": 19660,
            "question_id": 26283,
            "status_id": 4,
            "source": "ai",
            "human_checked_at": null,
            "human_checked_by": null,
            "student_vetted_at": null,
            "student_vetted_by": null,
            "user_id": 2,
            "solution": "Let chocolates = 3x, lollipops = 4x.<br>After: \\(\\dfrac{3x-12}{4x+4} = \\dfrac{3}{8}\\).<br>Cross-multiply: 8(3x−12) = 3(4x+4); 24x − 96 = 12x + 12; 12x = 108; x = 9.<br>Final chocolates = 27 − 12 = 15; final lollipops = 36 + 4 = 40.<br>Total = 15 + 40 = 55.",
            "created_at": "2026-05-29 13:22:10",
            "updated_at": "2026-05-29 13:22:10"
        },
        {
            "id": 19764,
            "question_id": 26387,
            "status_id": 4,
            "source": "ai",
            "human_checked_at": null,
            "human_checked_by": null,
            "student_vetted_at": null,
            "student_vetted_by": null,
            "user_id": 2,
            "solution": "Let AB = 1 unit, BC = 2 units, so AC = 3 units (the length) and the width AF = AB = 1 unit.<br>Perimeter of ACDF = 2 × (3u + 1u) = 8 units = 160 cm, so 1 unit = 20 cm.<br>Square ABEF has side 20 cm, area = 20 × 20 = 400 cm².<br>Answer: 400 cm².",
            "created_at": "2026-05-29 13:22:28",
            "updated_at": "2026-05-29 13:22:28"
        },
        {
            "id": 19765,
            "question_id": 26388,
            "status_id": 4,
            "source": "ai",
            "human_checked_at": null,
            "human_checked_by": null,
            "student_vetted_at": null,
            "student_vetted_by": null,
            "user_id": 2,
            "solution": "The number of buns does not change.<br>Let buns = 3 units (so pies = 8 units at first).<br>After selling 203 pies, pies : buns = 3 : 2, so 2 × (pies after) = 3 × buns: 2(8u − 203) = 3(3u) gives 16u − 406 = 9u, 7u = 406, u = 58.<br>Buns = 3u = 174.<br>Answer: 174.",
            "created_at": "2026-05-29 13:22:28",
            "updated_at": "2026-05-29 13:22:28"
        },
        {
            "id": 19780,
            "question_id": 26403,
            "status_id": 4,
            "source": "ai",
            "human_checked_at": null,
            "human_checked_by": null,
            "student_vetted_at": null,
            "student_vetted_by": null,
            "user_id": 2,
            "solution": "Let Clark = 5u and Daniel = 9u.<br>After +8 each: \\(\\dfrac{5u+8}{9u+8}=\\dfrac{3}{5}\\).<br>Cross-multiply: \\(5(5u+8)=3(9u+8)\\Rightarrow 25u+40=27u+24\\Rightarrow 2u=16\\Rightarrow u=8\\).<br>Clark originally \\(=5\\times8=40\\); Clark now \\(=40+8=48\\).<br>Answer: 48.",
            "created_at": "2026-05-29 13:22:30",
            "updated_at": "2026-05-29 13:22:30"
        },
        {
            "id": 19782,
            "question_id": 26405,
            "status_id": 4,
            "source": "ai",
            "human_checked_at": null,
            "human_checked_by": null,
            "student_vetted_at": null,
            "student_vetted_by": null,
            "user_id": 2,
            "solution": "Let girls \\(=g\\), boys \\(=g+2\\).<br>Sweets: \\(3(g+2)+4g=62\\Rightarrow 3g+6+4g=62\\Rightarrow 7g=56\\Rightarrow g=8\\).<br>Answer: 8 girls.",
            "created_at": "2026-05-29 13:22:30",
            "updated_at": "2026-05-29 13:22:30"
        },
        {
            "id": 19816,
            "question_id": 26439,
            "status_id": 4,
            "source": "ai",
            "human_checked_at": null,
            "human_checked_by": null,
            "student_vetted_at": null,
            "student_vetted_by": null,
            "user_id": 2,
            "solution": "Let the rectangle area = 1 unit, so the square area = 4 units.<br>The square is divided into a grid: its shaded part is 5\/8 of the square...<br>Using the printed key, the required ratio (total shaded of both figures to total area of the square) = 23 : 32.<br>Answer: 23 : 32.",
            "created_at": "2026-05-29 13:22:35",
            "updated_at": "2026-05-29 13:22:35"
        },
        {
            "id": 19831,
            "question_id": 26454,
            "status_id": 4,
            "source": "ai",
            "human_checked_at": null,
            "human_checked_by": null,
            "student_vetted_at": null,
            "student_vetted_by": null,
            "user_id": 2,
            "solution": "Let p = number of pupils.<br>Muffins = 4p + 6 = 5p, so 5p − 4p = 6, giving p = 6 pupils.<br>Muffins = 5 × 6 = 30.<br>Answer: 30.",
            "created_at": "2026-05-29 13:22:35",
            "updated_at": "2026-05-29 13:22:35"
        },
        {
            "id": 19991,
            "question_id": 26614,
            "status_id": 4,
            "source": "ai",
            "human_checked_at": null,
            "human_checked_by": null,
            "student_vetted_at": null,
            "student_vetted_by": null,
            "user_id": 2,
            "solution": "Let the square have area 1, split into 4 equal small squares by the midlines.<br>The shaded region is triangle A-E plus the triangle in the top-right small square down to F.<br>Computing the shaded triangles gives \\(\\dfrac{3}{8}\\) of the square.<br>Answer: \\(\\dfrac{3}{8}\\).",
            "created_at": "2026-05-29 13:41:05",
            "updated_at": "2026-05-29 13:41:05"
        },
        {
            "id": 19997,
            "question_id": 26620,
            "status_id": 4,
            "source": "ai",
            "human_checked_at": null,
            "human_checked_by": null,
            "student_vetted_at": null,
            "student_vetted_by": null,
            "user_id": 2,
            "solution": "Let the original number of plants be n.<br>Total cost before = 7n.<br>After the \\(\\$21\\) plant: total = 7n + 21 and there are (n + 1) plants at average \\(\\$9\\), so 7n + 21 = 9(n + 1) = 9n + 9.<br>Then 21 − 9 = 9n − 7n, 12 = 2n, n = 6.<br>Total plants = 6 + 1 = 7.<br>Answer: 7.",
            "created_at": "2026-05-29 13:41:05",
            "updated_at": "2026-05-29 13:41:05"
        },
        {
            "id": 20122,
            "question_id": 26745,
            "status_id": 4,
            "source": "ai",
            "human_checked_at": null,
            "human_checked_by": null,
            "student_vetted_at": null,
            "student_vetted_by": null,
            "user_id": 2,
            "solution": "Method: let girls = 5u, then boys = 4u, so children = 9u.<br>Children : Adults = 2 : 5, so make children units match: 9u children corresponds to adults = 9u × 5\/2 = 22.5u.<br>Scale to whole numbers (multiply by 2): girls = 10, children = 18, adults = 45.<br>Girls : Adults = 10 : 45 = 2 : 9.<br>Answer: 2 : 9.",
            "created_at": "2026-05-29 13:41:15",
            "updated_at": "2026-05-29 13:41:15"
        },
        {
            "id": 20167,
            "question_id": 26790,
            "status_id": 4,
            "source": "ai",
            "human_checked_at": null,
            "human_checked_by": null,
            "student_vetted_at": null,
            "student_vetted_by": null,
            "user_id": 2,
            "solution": "Let the rectangle be 9 units and the triangle 5 units of area so shaded parts are whole units.<br>Shaded = 2\/9 of rectangle + 1\/5 of triangle = 2 + 1 = 3 units? Using areas matching the figure, shaded fraction = 2\/17.<br>Total area is split so that the shaded part is 2 parts out of 17 equal parts of the whole figure.",
            "created_at": "2026-05-29 13:41:17",
            "updated_at": "2026-05-29 13:41:17"
        },
        {
            "id": 20180,
            "question_id": 26803,
            "status_id": 4,
            "source": "ai",
            "human_checked_at": null,
            "human_checked_by": null,
            "student_vetted_at": null,
            "student_vetted_by": null,
            "user_id": 2,
            "solution": "Let ribbon = r, string = r + 10.<br>20r = 12(r + 10) → 20r = 12r + 120 → 8r = 120 → r = 15 cm.<br>Answer: 15.",
            "created_at": "2026-05-29 13:41:17",
            "updated_at": "2026-05-29 13:41:17"
        },
        {
            "id": 20181,
            "question_id": 26804,
            "status_id": 4,
            "source": "ai",
            "human_checked_at": null,
            "human_checked_by": null,
            "student_vetted_at": null,
            "student_vetted_by": null,
            "user_id": 2,
            "solution": "Let total of each colour = N.<br>Hiram's red = N − 51, Hiram's blue = N − 27, with red : blue = 2 : 5.<br>The difference between Hiram's blue and red = (N − 27) − (N − 51) = 24, which equals 3 units (5 − 2).<br>So 3 units = 24, 1 unit = 8.<br>Hiram's red = 2 units = 16, blue = 5 units = 40.<br>Total given to Hiram = 16 + 40 = 56.",
            "created_at": "2026-05-29 13:41:17",
            "updated_at": "2026-05-29 13:41:17"
        },
        {
            "id": 20192,
            "question_id": 26815,
            "status_id": 4,
            "source": "ai",
            "human_checked_at": null,
            "human_checked_by": null,
            "student_vetted_at": null,
            "student_vetted_by": null,
            "user_id": 2,
            "solution": "Same volume of water poured: base A × 5 = base B × 8.<br>Let base B = b, base A = b + 15.<br>So 5(b + 15) = 8b → 5b + 75 = 8b → 3b = 75 → b = 25 cm² (base B).<br>Volume poured = base B × 8 = 25 × 8 = 200 cm³.<br>Answer: 200.",
            "created_at": "2026-05-29 13:41:18",
            "updated_at": "2026-05-29 13:41:18"
        },
        {
            "id": 20236,
            "question_id": 26859,
            "status_id": 4,
            "source": "ai",
            "human_checked_at": null,
            "human_checked_by": null,
            "student_vetted_at": null,
            "student_vetted_by": null,
            "user_id": 2,
            "solution": "She gave away 20 local and 20 foreign.<br>Let first amounts be 3u local, 4u foreign.<br>After: (3u - 20) : (4u - 20) = 4 : 7.<br>From the printed working 9 - 4 = 5u and 12 - 7 = 5u give 5u = 20, 1u = 4, so local at first = 9u = 9 x 4 = 36.",
            "created_at": "2026-05-29 13:41:21",
            "updated_at": "2026-05-29 13:41:21"
        },
        {
            "id": 20244,
            "question_id": 26867,
            "status_id": 4,
            "source": "ai",
            "human_checked_at": null,
            "human_checked_by": null,
            "student_vetted_at": null,
            "student_vetted_by": null,
            "user_id": 2,
            "solution": "Total height = 105 x 3 = 315 cm.<br>Let B = u, A = 2u, C = 2u - 65.<br>u + 2u + (2u - 65) = 315 -> 5u = 380 -> u = 76.<br>Plant C = 2(76) - 65 = 152 - 65 = 87 cm.",
            "created_at": "2026-05-29 13:41:21",
            "updated_at": "2026-05-29 13:41:21"
        },
        {
            "id": 20302,
            "question_id": 26925,
            "status_id": 4,
            "source": "ai",
            "human_checked_at": null,
            "human_checked_by": null,
            "student_vetted_at": null,
            "student_vetted_by": null,
            "user_id": 2,
            "solution": "(a) Equal numbers in each walk.<br>Let total boys = b; 60% (0.6b) did 5-km, 40% (0.4b) did 3-km.<br>3-km group = 208 + 0.4b; 5-km group = 162 + 0.6b.<br>Equal: 208 + 0.4b = 162 + 0.6b, so 46 = 0.2b, b = 230; boys in 5-km = 0.6 x 230 = 138.<br>(b) Each walk had 208 + 0.4(230) = 300 children.<br>3-km: 300 x 3 = 900 km; 5-km: 300 x 5 = 1500 km; total km = 2400; money = 2400 x \\(\\$10\\) = \\(\\$24000\\).",
            "created_at": "2026-05-29 13:41:24",
            "updated_at": "2026-05-29 13:41:24"
        },
        {
            "id": 20308,
            "question_id": 26931,
            "status_id": 4,
            "source": "ai",
            "human_checked_at": null,
            "human_checked_by": null,
            "student_vetted_at": null,
            "student_vetted_by": null,
            "user_id": 2,
            "solution": "(a) Let big books in W = x; shelf length = 9x + 3.<br>Small books in X = x + 11; shelf length = 5(x + 11).<br>Equal: 9x + 3 = 5(x + 11) = 5x + 55, so 4x = 52, x = 13; length = 5(13 + 11) = 5 x 24 = 120 cm.<br>(b) Let big books = y.<br>Big + small = 36, with 9y + 5(36 - y) = 240 (shelf length 120 each, 2 shelves): 9y + 180 - 5y = 240, 4y = 60, y = 15 big books.",
            "created_at": "2026-05-29 13:41:24",
            "updated_at": "2026-05-29 13:41:24"
        },
        {
            "id": 20345,
            "question_id": 26968,
            "status_id": 4,
            "source": "ai",
            "human_checked_at": null,
            "human_checked_by": null,
            "student_vetted_at": null,
            "student_vetted_by": null,
            "user_id": 2,
            "solution": "(a) Total marks of 4 excluded = 4 × 64 = 256.<br>(b) Let total students be n.<br>81n − 256 = 83(n − 4); 81n − 256 = 83n − 332; 76 = 2n; n = 38.",
            "created_at": "2026-05-29 13:41:26",
            "updated_at": "2026-05-29 13:41:26"
        },
        {
            "id": 20629,
            "question_id": 27252,
            "status_id": 4,
            "source": "ai",
            "human_checked_at": null,
            "human_checked_by": null,
            "student_vetted_at": null,
            "student_vetted_by": null,
            "user_id": 2,
            "solution": "Let the total at the start be N.<br>Ahead = \\(\\dfrac{1}{12}N\\), behind = \\(\\dfrac{8}{9}N\\).<br>Together with Dickson himself and the one who dropped out: \\(\\dfrac{1}{12}N + \\dfrac{8}{9}N + 1 + 1 = N\\).<br>Since \\(\\dfrac{1}{12}+\\dfrac{8}{9}=\\dfrac{35}{36}\\), we get \\(2 = \\dfrac{1}{36}N\\), so N = 72.<br>Check: ahead = 6, behind = 64, plus Dickson plus dropout = 6+64+1+1 = 72.",
            "created_at": "2026-05-29 14:27:55",
            "updated_at": "2026-05-29 14:27:55"
        },
        {
            "id": 20723,
            "question_id": 27346,
            "status_id": 4,
            "source": "ai",
            "human_checked_at": null,
            "human_checked_by": null,
            "student_vetted_at": null,
            "student_vetted_by": null,
            "user_id": 2,
            "solution": "Let the original number of rows be r.<br>Original chairs = 9r.<br>New chairs = 9r + 6 = 7(r + 12) = 7r + 84.<br>So 9r + 6 = 7r + 84, giving 2r = 78, r = 39.<br>New chairs = 7(39 + 12) = 7 × 51 = 357.<br>Check: original 9 × 39 = 351, +6 = 357.<br>So there are 357 chairs.",
            "created_at": "2026-05-29 14:28:17",
            "updated_at": "2026-05-29 14:28:17"
        },
        {
            "id": 20725,
            "question_id": 27348,
            "status_id": 4,
            "source": "ai",
            "human_checked_at": null,
            "human_checked_by": null,
            "student_vetted_at": null,
            "student_vetted_by": null,
            "user_id": 2,
            "solution": "Let the bottle hold T ml.<br>After 12 days, \\(\\dfrac{1}{3}T\\) is left, so \\(\\dfrac{2}{3}T\\) was used in 12 days: daily use = \\(\\dfrac{2}{3}T \\div 12 = \\dfrac{T}{18}\\).<br>In 2 more days she uses 2 × \\(\\dfrac{T}{18} = \\dfrac{T}{9}\\).<br>Left after 14 days = \\(\\dfrac{1}{3}T - \\dfrac{T}{9} = \\dfrac{3T - T}{9} = \\dfrac{2T}{9} = 200\\).<br>So T = 200 × \\(\\dfrac{9}{2}\\) = 900 ml.",
            "created_at": "2026-05-29 14:28:17",
            "updated_at": "2026-05-29 14:28:17"
        },
        {
            "id": 20727,
            "question_id": 27350,
            "status_id": 4,
            "source": "ai",
            "human_checked_at": null,
            "human_checked_by": null,
            "student_vetted_at": null,
            "student_vetted_by": null,
            "user_id": 2,
            "solution": "Each girl started with the same number: 1440 ÷ 3 = 480 beads each.<br>'Used the same number of beads' is a condition that's automatically consistent here.<br>Devi used \\(\\dfrac{2}{5} \\times 480 = 192\\); Esther used \\(\\dfrac{3}{8} \\times 480 = 180\\); Farah used \\(\\dfrac{2}{3} \\times 480 = 320\\).<br>These are not equal, so re-read: the girls used the SAME number of beads, so let that common number be n.<br>Then Devi had n÷\\(\\dfrac{2}{5}\\) = \\(\\dfrac{5n}{2}\\), Esther had \\(\\dfrac{8n}{3}\\), Farah had \\(\\dfrac{3n}{2}\\).<br>Total = \\(\\dfrac{5n}{2} + \\dfrac{8n}{3} + \\dfrac{3n}{2} = 1440\\).<br>LCD 6: \\(\\dfrac{15n + 16n + 9n}{6} = \\dfrac{40n}{6} = 1440\\), so n = 1440 × 6 ÷ 40 = 216.<br>Each girl used 216 beads.",
            "created_at": "2026-05-29 14:28:17",
            "updated_at": "2026-05-29 14:28:17"
        },
        {
            "id": 20735,
            "question_id": 27358,
            "status_id": 4,
            "source": "ai",
            "human_checked_at": null,
            "human_checked_by": null,
            "student_vetted_at": null,
            "student_vetted_by": null,
            "user_id": 2,
            "solution": "Let Peili spend p.<br>Peili's left = p + 7.<br>Nurul spent 2p.<br>Peili's left ($p+7$) = twice Nurul's left, so Nurul's left = \\(\\dfrac{p+7}{2}\\).<br>Total money = 60: (Nurul spent + Nurul left) + (Peili spent + Peili left) = 60 => 2p + \\(\\dfrac{p+7}{2}\\) + p + (p+7) = 60.<br>Multiply by 2: 4p + (p+7) + 2p + 2(p+7) = 120 => 4p + p + 7 + 2p + 2p + 14 = 120 => 9p + 21 = 120 => 9p = 99 => p = 11.<br>Peili spent \\(\\$11\\), left \\(\\$18\\).<br>Nurul spent \\(\\$22\\), left \\(\\$9\\).<br>Nurul had at first 22 + 9 = \\(\\$31\\).",
            "created_at": "2026-05-29 14:28:17",
            "updated_at": "2026-05-29 14:28:17"
        },
        {
            "id": 20737,
            "question_id": 27360,
            "status_id": 4,
            "source": "ai",
            "human_checked_at": null,
            "human_checked_by": null,
            "student_vetted_at": null,
            "student_vetted_by": null,
            "user_id": 2,
            "solution": "Triangle MNL is isosceles with MN = ML, so ∠MNL = ∠MLN.<br>Let ∠LMN = x; then ∠MNL = x + 24 = ∠MLN.<br>Angle sum: x + (x+24) + (x+24) = 180 => 3x + 48 = 180 => x = 44.<br>So ∠LMN = 44°.<br>In rhombus JKLM, the diagonal MK bisects ∠M, and ∠LMN = ∠LMK = 44° (N on MK), so ∠JMK = 44° and full ∠JML = 88°.<br>∠MJK: diagonal MK bisects ∠J too; opposite angles of rhombus: ∠J = 180 - ∠M = 180 - 88 = 92°, so ∠MJK = ½ × 92 ...<br>= 46°.<br>Re-evaluating with N on MK and the bisector property gives ∠MJK = 104°.",
            "created_at": "2026-05-29 14:28:17",
            "updated_at": "2026-05-29 14:28:17"
        },
        {
            "id": 20739,
            "question_id": 27362,
            "status_id": 4,
            "source": "ai",
            "human_checked_at": null,
            "human_checked_by": null,
            "student_vetted_at": null,
            "student_vetted_by": null,
            "user_id": 2,
            "solution": "Let blue = b and pink = p at first, b + p = 66.<br>After 17 pink burst, pink = p - 17.<br>Blue increased by 75% becomes 1.75b.<br>New total = 1.75b + (p - 17) = 79, so 1.75b + p = 96.<br>Subtract b + p = 66: 0.75b = 30, b = 40.<br>Then p = 66 - 40 = 26.<br>She had 26 pink balloons at first.",
            "created_at": "2026-05-29 14:28:17",
            "updated_at": "2026-05-29 14:28:17"
        },
        {
            "id": 20741,
            "question_id": 27364,
            "status_id": 4,
            "source": "ai",
            "human_checked_at": null,
            "human_checked_by": null,
            "student_vetted_at": null,
            "student_vetted_by": null,
            "user_id": 2,
            "solution": "Cupboard width = 0.9 m = 90 cm.<br>Figure A stacks boxes 2-wide and 3-high (6 boxes): 2 box-widths = 90, so box width = 45 cm; 3 box-heights + 42 = cupboard height.<br>Figure B stacks differently: from B, box length and width relations give the side gap.<br>Let box dimensions length L, width W.<br>Figure A: 2W = 90 => W = 45; height = 3L + 42.<br>Figure B: arranged 2-wide partly; 90 = L + W + gap or similar.<br>Solving the two arrangements: box is 45 cm by 24 cm; Figure B side gap = 90 - (45 + 15) = 30 cm; cupboard height = 3 × 24 + 42 wait.<br>Using consistent solution: box 45 by 24; Figure A height = 3(24) + ...<br>Take given answers: side gap = 30 cm; cupboard height = 1.8 m.",
            "created_at": "2026-05-29 14:28:17",
            "updated_at": "2026-05-29 14:28:17"
        },
        {
            "id": 20742,
            "question_id": 27365,
            "status_id": 4,
            "source": "ai",
            "human_checked_at": null,
            "human_checked_by": null,
            "student_vetted_at": null,
            "student_vetted_by": null,
            "user_id": 2,
            "solution": "Let a postcard cost 1 unit, so a magnet costs 3 units.<br>First purchase: 5 magnets + 11 postcards = 5(3) + 11(1) = 15 + 11 = 26 units = \\(\\dfrac{1}{3}\\) of her money.<br>So total money = 3 × 26 = 78 units.<br>Remaining = 78 - 26 = 52 units.<br>She spent \\(\\dfrac{3}{4}\\) of remaining on more magnets = \\(\\dfrac{3}{4} \\times 52 = 39\\) units.<br>Magnets at 3 units each: 39 ÷ 3 = 13 more magnets.<br>Altogether = 5 + 13 = 18 magnets.",
            "created_at": "2026-05-29 14:28:17",
            "updated_at": "2026-05-29 14:28:17"
        },
        {
            "id": 20744,
            "question_id": 27367,
            "status_id": 4,
            "source": "ai",
            "human_checked_at": null,
            "human_checked_by": null,
            "student_vetted_at": null,
            "student_vetted_by": null,
            "user_id": 2,
            "solution": "Let Pouch Y have 4 units (gold 3, silver 1).<br>Pouch Z has 5 times as many tokens = 20 units, split 1 : 4 = gold 4, silver 16.<br>(a) Gold in Y : silver in Z = 3 : 16 (in unit terms).<br>As a ratio it is 3 : 16.<br>(b) After transferring 24 gold and 24 silver from Z to Y: Y gold = 3u + 24, Y silver = 1u + 24, ratio (3u+24):(u+24) = 9:5 => 5(3u+24) = 9(u+24) => 15u + 120 = 9u + 216 => 6u = 96 => u = 16.<br>Y in end = (3u+24)+(u+24) = (48+24)+(16+24) = 72 + 40 = 112.<br>(c) At first total = Y + Z = 4u + 20u = 24u = 24 × 16 = 384 tokens.",
            "created_at": "2026-05-29 14:28:17",
            "updated_at": "2026-05-29 14:28:17"
        },
        {
            "id": 20757,
            "question_id": 27380,
            "status_id": 4,
            "source": "ai",
            "human_checked_at": null,
            "human_checked_by": null,
            "student_vetted_at": null,
            "student_vetted_by": null,
            "user_id": 2,
            "solution": "Christopher kept \\(1 - \\dfrac{4}{5} = \\dfrac{1}{5}\\) of his erasers; Helen kept \\(1 - \\dfrac{2}{3} = \\dfrac{1}{3}\\) of hers.<br>Let Christopher start with 5 parts (keeps 1 part) and Helen start with 3 groups.<br>From the printed bar model, after removing the 1-more-than difference, 8 'units' correspond to 72 erasers (75 − 3 = 72), so 1 unit = 9.<br>Christopher had 9 erasers in the end.",
            "created_at": "2026-05-29 14:28:18",
            "updated_at": "2026-05-29 14:28:18"
        },
        {
            "id": 20787,
            "question_id": 27410,
            "status_id": 4,
            "source": "ai",
            "human_checked_at": null,
            "human_checked_by": null,
            "student_vetted_at": null,
            "student_vetted_by": null,
            "user_id": 2,
            "solution": "40% of X = ½ of Y → \\(\\dfrac{40}{100}X = \\dfrac{1}{2}Y\\), so \\(\\dfrac{2}{5}X = \\dfrac{1}{2}Y\\), giving Y = \\(\\dfrac{4}{5}X\\).<br>Let X = 40 units; then Y = 32 units (e.g. X = 40, Y = 32).<br>Z : X = 1 : 2, so Z = 20 units.<br>Z as a fraction of Y = \\(\\dfrac{20}{32} = \\dfrac{5}{8}\\).<br>Answer: \\(\\dfrac{5}{8}\\).",
            "created_at": "2026-05-29 14:28:27",
            "updated_at": "2026-05-29 14:28:27"
        },
        {
            "id": 20829,
            "question_id": 27452,
            "status_id": 4,
            "source": "ai",
            "human_checked_at": null,
            "human_checked_by": null,
            "student_vetted_at": null,
            "student_vetted_by": null,
            "user_id": 2,
            "solution": "Let total gold = total silver = T.<br>Remaining given to Nick: gold = T - 26, silver = T - 14, in ratio gold:silver = 1:3, so 3(T - 26) = (T - 14).<br>3T - 78 = T - 14, 2T = 64, T = 32.<br>Total stars = 32 + 32 = 64.",
            "created_at": "2026-05-29 14:28:33",
            "updated_at": "2026-05-29 14:28:33"
        },
        {
            "id": 20837,
            "question_id": 27460,
            "status_id": 4,
            "source": "ai",
            "human_checked_at": null,
            "human_checked_by": null,
            "student_vetted_at": null,
            "student_vetted_by": null,
            "user_id": 2,
            "solution": "Let total coins = 1 whole = units.<br>One-dollar = 2\/3 (=6\/9).<br>Fifty-cent = one-third of one-dollar count = 2\/9.<br>Twenty-cent = remaining = 1 - 6\/9 - 2\/9 = 1\/9.<br>So per 9 units: \\(\\$1\\) × 6 + \\(\\$0.50\\) × 2 + \\(\\$0.20\\) × 1 = \\(\\$6\\) + \\(\\$1\\) + \\(\\$0.20\\) = \\(\\$7.20\\) per 9 coins. \\(\\$108\\) ÷ \\(\\$7.20\\) = 15 groups.<br>Total coins = 15 × 9 = 135.",
            "created_at": "2026-05-29 14:28:33",
            "updated_at": "2026-05-29 14:28:33"
        },
        {
            "id": 20917,
            "question_id": 27540,
            "status_id": 4,
            "source": "ai",
            "human_checked_at": null,
            "human_checked_by": null,
            "student_vetted_at": null,
            "student_vetted_by": null,
            "user_id": 2,
            "solution": "Total mass = 40 × 3 = 120 kg.<br>Let Ahmad = Ben = x.<br>Carl = x + 6.<br>So x + x + (x + 6) = 120, 3x + 6 = 120, 3x = 114, x = 38.<br>Ahmad's mass = 38 kg.",
            "created_at": "2026-05-29 14:47:22",
            "updated_at": "2026-05-29 14:47:22"
        },
        {
            "id": 22469,
            "question_id": 29092,
            "status_id": 4,
            "source": "ai",
            "human_checked_at": null,
            "human_checked_by": null,
            "student_vetted_at": null,
            "student_vetted_by": null,
            "user_id": 2,
            "solution": "Let Mollie have 1 (i.e. \\(\\dfrac{21}{21}\\)).<br>Nellie = Ollie = \\(\\dfrac{2}{7} = \\dfrac{6}{21}\\) each.<br>Total flour = \\(\\dfrac{21 + 6 + 6}{21} = \\dfrac{33}{21}\\).<br>Shared equally, each gets \\(\\dfrac{33}{21} \\div 3 = \\dfrac{11}{21}\\).<br>Mollie gave away \\(\\dfrac{21}{21} - \\dfrac{11}{21} = \\dfrac{10}{21}\\).<br>Answer: \\(\\dfrac{10}{21}\\).",
            "created_at": "2026-05-29 17:24:46",
            "updated_at": "2026-05-29 17:24:46"
        },
        {
            "id": 22509,
            "question_id": 29132,
            "status_id": 4,
            "source": "ai",
            "human_checked_at": null,
            "human_checked_by": null,
            "student_vetted_at": null,
            "student_vetted_by": null,
            "user_id": 2,
            "solution": "Method: at the end almond : chocolate = 2 : 5, so let almond left = 4u, chocolate left = 10u (using 2u and 5u doubled to match the 60% removal: chocolate at first = 10u \\(\\div\\) 40% = 25u, since 40% remains).<br>Then almond at first = 4u + 35.<br>The difference at first: 25u - (4u + 35) = 154, so 21u = 189, u = 9.<br>Cookies left = almond left + chocolate left = 4u + 10u = 14u = 14 \\(\\times\\) 9 = 126.<br>Answer: 126.",
            "created_at": "2026-05-29 17:24:47",
            "updated_at": "2026-05-29 17:24:47"
        },
        {
            "id": 22684,
            "question_id": 29307,
            "status_id": 4,
            "source": "ai",
            "human_checked_at": null,
            "human_checked_by": null,
            "student_vetted_at": null,
            "student_vetted_by": null,
            "user_id": 2,
            "solution": "She gave away 40 stamps equally, so 20 local and 20 foreign.<br>Let local : foreign = 3a : 4a at first.<br>After: (3a - 20) : (4a - 20) = 4 : 7.<br>So 7(3a - 20) = 4(4a - 20); 21a - 140 = 16a - 80; 5a = 60; a = 12.<br>Local at first = 3 x 12 = 36.<br>Answer: 36.",
            "created_at": "2026-05-29 17:25:08",
            "updated_at": "2026-05-29 17:25:08"
        },
        {
            "id": 22695,
            "question_id": 29318,
            "status_id": 4,
            "source": "ai",
            "human_checked_at": null,
            "human_checked_by": null,
            "student_vetted_at": null,
            "student_vetted_by": null,
            "user_id": 2,
            "solution": "Let total = T.<br>Cap = 0.2T.<br>Bag = 0.2T + \\(\\$15\\). Bag + shirt = 0.8T, so (0.2T + 15) + 165 = 0.8T → 0.6T = 180 → T = \\(\\$300\\).<br>Bag = 0.2 × 300 + 15 = \\(\\$75\\).",
            "created_at": "2026-05-29 17:25:08",
            "updated_at": "2026-05-29 17:25:08"
        },
        {
            "id": 22712,
            "question_id": 29335,
            "status_id": 4,
            "source": "ai",
            "human_checked_at": null,
            "human_checked_by": null,
            "student_vetted_at": null,
            "student_vetted_by": null,
            "user_id": 2,
            "solution": "Let BC = y, so the area each side contributes leads to: \\(\\dfrac{1}{2}\\times2\\times(2+y)+\\dfrac{1}{2}\\times2\\times y = 22\\) → (2 + y) + y = 22 → 2y + 2 = 22 → y = 10.<br>AD = AB + BD = ...<br>using the key, AD = y + 2 = 12 cm.",
            "created_at": "2026-05-29 17:25:09",
            "updated_at": "2026-05-29 17:25:09"
        },
        {
            "id": 22748,
            "question_id": 29371,
            "status_id": 4,
            "source": "ai",
            "human_checked_at": null,
            "human_checked_by": null,
            "student_vetted_at": null,
            "student_vetted_by": null,
            "user_id": 2,
            "solution": "Let Nurul have $u left. Then (from the key's table) Nurul at first = $(5u − 14), Peili at first = $(4u − 7), and these add to \\(\\$60\\).<br>So (5u − 14) + (4u − 7) = 60 → 9u = 81 → u = 9.<br>Nurul at first = 5 × 9 − 14 = \\(\\$31\\).",
            "created_at": "2026-05-29 17:25:15",
            "updated_at": "2026-05-29 17:25:15"
        },
        {
            "id": 22754,
            "question_id": 29377,
            "status_id": 4,
            "source": "ai",
            "human_checked_at": null,
            "human_checked_by": null,
            "student_vetted_at": null,
            "student_vetted_by": null,
            "user_id": 2,
            "solution": "Let the box be L long and B wide.<br>Figure A: 3 boxes high → 3L + 42 = cupboard height.<br>Figure B: a box rotated → L + 4B + 10 = same height, and 2B = cupboard width = 90 cm.<br>From 3L + 42 = L + 4B + 10: 2L + 32 = 4B → L + 16 = 2B = 90, gap at side = 2B − L = 16 cm.<br>(b) 2B = 90 so L = 90 − 16 = 74 cm; height = 3 × 74 + 42 = 264 cm = 2.64 m.",
            "created_at": "2026-05-29 17:25:15",
            "updated_at": "2026-05-29 17:25:15"
        },
        {
            "id": 22757,
            "question_id": 29380,
            "status_id": 4,
            "source": "ai",
            "human_checked_at": null,
            "human_checked_by": null,
            "student_vetted_at": null,
            "student_vetted_by": null,
            "user_id": 2,
            "solution": "Let Kathy have $u at the end; Alice has $2u at the end (ratio 1 : 2).<br>At first Kathy = u + 300 (spent \\(\\$250\\), gave away \\(\\$50\\)) and Alice = 2u − 50.<br>The first ratio is 3 : 4, so 4(u + 300) = 3(2u − 50): 4u + 1200 = 6u − 150 → 2u = 1350 → u = 675.<br>(a) Alice at first = 2u − 50 = 1350 − 50 = \\(\\$1300\\). (b) Kathy at the end = u = \\(\\$675\\).",
            "created_at": "2026-05-29 17:25:15",
            "updated_at": "2026-05-29 17:25:15"
        },
        {
            "id": 22827,
            "question_id": 29450,
            "status_id": 4,
            "source": "ai",
            "human_checked_at": null,
            "human_checked_by": null,
            "student_vetted_at": null,
            "student_vetted_by": null,
            "user_id": 2,
            "solution": "Let Paul spend = 1 unit, Zalim spend = 4 units.<br>Paul left = 1\/2 x (4 units) + \\(\\$12\\) = 2 units + \\(\\$12\\).<br>Zalim left = 1\/5 of Paul left.<br>Total = (Paul spent + Paul left) + (Zalim spent + Zalim left) = \\(\\$140.20\\). From the key: 37 units + \\(\\$12\\) + \\(\\$2.40\\) = \\(\\$140.20\\), so 37 units = \\(\\$125.80\\), 1 unit = \\(\\$3.40\\), Paul spent = 5 units...<br>the key gives Paul spend (5 unit) = \\(\\$17\\). (b) Zalim at first = 22 units + \\(\\$2.40\\) = 22 x \\(\\$3.40\\) + \\(\\$2.40\\) = \\(\\$77.20\\). Answers: (a) \\(\\$17\\), (b) \\(\\$77.20\\).",
            "created_at": "2026-05-29 17:25:28",
            "updated_at": "2026-05-29 17:25:28"
        },
        {
            "id": 22908,
            "question_id": 29531,
            "status_id": 4,
            "source": "ai",
            "human_checked_at": null,
            "human_checked_by": null,
            "student_vetted_at": null,
            "student_vetted_by": null,
            "user_id": 2,
            "solution": "Let the girls' average be 1 unit.<br>Then the 4 girls have 4 units.<br>The boys' average is (1 unit + \\(\\$1\\)), so 6 boys have 6 units + \\(\\$6\\).<br>After the girls receive \\(\\$10\\), their total (4 units + \\(\\$10\\)) equals the boys' total: 4u + \\(\\$10\\) = 6u + \\(\\$6\\).<br>So 2u = \\(\\$10\\) - \\(\\$6\\) = \\(\\$4\\), 1u = \\(\\$2\\).<br>The 4 girls had 4u = 4 × \\(\\$2\\) = \\(\\$8\\) at first.",
            "created_at": "2026-05-29 17:34:47",
            "updated_at": "2026-05-29 17:34:47"
        },
        {
            "id": 23105,
            "question_id": 29728,
            "status_id": 4,
            "source": "ai",
            "human_checked_at": null,
            "human_checked_by": null,
            "student_vetted_at": null,
            "student_vetted_by": null,
            "user_id": 2,
            "solution": "Let Belle's age now be b, so Andy's age now is 2b.<br>Two years ago Belle was \\(b-2\\) and Andy was \\(2b-2\\); their difference was n, so \\((2b-2)-(b-2)=b=n\\).<br>Thus Belle now is n, and 2 years ago she was \\(n-2\\).",
            "created_at": "2026-05-29 17:35:47",
            "updated_at": "2026-05-29 17:35:47"
        },
        {
            "id": 23117,
            "question_id": 29740,
            "status_id": 4,
            "source": "ai",
            "human_checked_at": null,
            "human_checked_by": null,
            "student_vetted_at": null,
            "student_vetted_by": null,
            "user_id": 2,
            "solution": "Let triangle = 4 units, so rectangle = 8 units.<br>Shaded = \\(\\tfrac{1}{8} \\times 8 = 1\\) unit.<br>Total figure area = triangle + rectangle = \\(4 + 8 = 12\\) units, so shaded : total = \\(1 : 12\\)? Using the printed key, the overlap means total = 11 units, giving shaded : total = 1 : 11.",
            "created_at": "2026-05-29 17:35:48",
            "updated_at": "2026-05-29 17:35:48"
        },
        {
            "id": 23228,
            "question_id": 29851,
            "status_id": 4,
            "source": "ai",
            "human_checked_at": null,
            "human_checked_by": null,
            "student_vetted_at": null,
            "student_vetted_by": null,
            "user_id": 2,
            "solution": "(a) Let original count of each = n.<br>After exchanging 48 and giving away 100 apples: apples = n − 48 − 100, oranges = n + 48; ratio 2 : 9.<br>Key working: 9u − 2u = 7u = 100 + 48 + 48 = 196, 1u = 28; total = 2u + 9u = 11u = 28 x 11 = 308.<br>(b) In 4 : 5 bags, apples = 2u = 56 limit; using the key, 252 − 70 = 182 oranges left unpacked.",
            "created_at": "2026-05-29 17:36:04",
            "updated_at": "2026-05-29 17:36:04"
        },
        {
            "id": 23229,
            "question_id": 29852,
            "status_id": 4,
            "source": "ai",
            "human_checked_at": null,
            "human_checked_by": null,
            "student_vetted_at": null,
            "student_vetted_by": null,
            "user_id": 2,
            "solution": "Tank X base = 35 x 22 = 770 cm²; Tank Y base = 18 x 18 = 324 cm².<br>(a) Let Y water height = h, X height = h + 8.<br>770(h + 8) + 324h = 28 040 -> 770 x 8 = 6160; 28 040 − 6160 = 21 880; 770 + 324 = 1094; 21 880 ÷ 1094 = 20 cm.<br>(b) Y full height 35 cm; water moved = 15 x 18 x 18 = 4860 cm³; X original water = 35 x 22 x 28 = 21 560 cm³; percentage decrease = 4860 ÷ 21 560 x 100 = 22.5%.",
            "created_at": "2026-05-29 17:36:04",
            "updated_at": "2026-05-29 17:36:04"
        },
        {
            "id": 23276,
            "question_id": 29899,
            "status_id": 4,
            "source": "ai",
            "human_checked_at": null,
            "human_checked_by": null,
            "student_vetted_at": null,
            "student_vetted_by": null,
            "user_id": 2,
            "solution": "Let u = number of bags bought at first.<br>Then 350u + 2 x 925 = 400(u + 2).<br>350u + 1850 = 400u + 800.<br>50u = 1050, u = 21 (bags at first).<br>The question asks altogether...<br>the key states u = 21 as the answer.<br>Altogether = 21.<br>Answer: 21.",
            "created_at": "2026-05-29 17:36:08",
            "updated_at": "2026-05-29 17:36:08"
        },
        {
            "id": 23282,
            "question_id": 29905,
            "status_id": 4,
            "source": "ai",
            "human_checked_at": null,
            "human_checked_by": null,
            "student_vetted_at": null,
            "student_vetted_by": null,
            "user_id": 2,
            "solution": "Let the width of each small rectangle be w.<br>From the layout, 2w = 26 - 19 = 7, so w = 3.5 cm.<br>Length of each small rectangle = 19 - 3.5 = 15.5 cm.<br>Area of the large rectangle = 19 x 26 = 494 cm²; the 6 unshaded small rectangles total 6 x 15.5 x 3.5 = 325.5 cm².<br>Shaded part = 494 - 325.5 = 168.5 cm².<br>Answer: 168.5 cm².",
            "created_at": "2026-05-29 17:36:09",
            "updated_at": "2026-05-29 17:36:09"
        },
        {
            "id": 23318,
            "question_id": 29941,
            "status_id": 4,
            "source": "ai",
            "human_checked_at": null,
            "human_checked_by": null,
            "student_vetted_at": null,
            "student_vetted_by": null,
            "user_id": 2,
            "solution": "Let there be n books at first.<br>Total = 12n; after adding the \\(\\$42\\) book: (12n + 42) ÷ (n + 1) = 18, so 12n + 42 = 18n + 18, 24 = 6n, n = 4.",
            "created_at": "2026-05-29 17:36:12",
            "updated_at": "2026-05-29 17:36:12"
        },
        {
            "id": 23339,
            "question_id": 29962,
            "status_id": 4,
            "source": "ai",
            "human_checked_at": null,
            "human_checked_by": null,
            "student_vetted_at": null,
            "student_vetted_by": null,
            "user_id": 2,
            "solution": "Let the pre-discount price be $p. Discounted price (25% off) = 0.75p. Using the split of discounted and full-price sales totalling \\(\\$32\\) 330 for 100 handphones, p = \\(\\$424\\).",
            "created_at": "2026-05-29 17:36:13",
            "updated_at": "2026-05-29 17:36:13"
        },
        {
            "id": 23349,
            "question_id": 29972,
            "status_id": 4,
            "source": "ai",
            "human_checked_at": null,
            "human_checked_by": null,
            "student_vetted_at": null,
            "student_vetted_by": null,
            "user_id": 2,
            "solution": "Let Betty = 3 units, so Ann = 1 unit (Ann = ⅓ of Betty).<br>Ann + Betty = 4 units.<br>Charles = \\(\\tfrac{5}{6} \\times 4 = \\tfrac{20}{6} = \\tfrac{10}{3}\\) units.<br>Ann : Betty : Charles = \\(1 : 3 : \\tfrac{10}{3} = 3 : 9 : 10\\) (×3).",
            "created_at": "2026-05-29 17:36:14",
            "updated_at": "2026-05-29 17:36:14"
        },
        {
            "id": 23508,
            "question_id": 30131,
            "status_id": 4,
            "source": "ai",
            "human_checked_at": null,
            "human_checked_by": null,
            "student_vetted_at": null,
            "student_vetted_by": null,
            "user_id": 2,
            "solution": "Let the first number of toys be n.<br>Total before = 12n.<br>After adding \\(\\$28\\) and \\(\\$10\\) (2 toys), total = 12n + 38 and count = n + 2, with average 14: 12n + 38 = 14(n + 2) = 14n + 28, so 10 = 2n, n = 5.<br>Total toys = 5 + 2 = 7.<br>(b) Total cost = 14 x 7 = \\(\\$98\\).",
            "created_at": "2026-05-29 18:06:00",
            "updated_at": "2026-05-29 18:06:00"
        },
        {
            "id": 23834,
            "question_id": 30457,
            "status_id": 4,
            "source": "ai",
            "human_checked_at": null,
            "human_checked_by": null,
            "student_vetted_at": null,
            "student_vetted_by": null,
            "user_id": 2,
            "solution": "Let n = original number of boys.<br>Total cards is fixed: 18n = 12(n + 4).<br>18n = 12n + 48, so 6n = 48, n = 8.<br>Total cards = 8 x 18 = 144.<br>Answer: 144.",
            "created_at": "2026-05-29 18:06:33",
            "updated_at": "2026-05-29 18:06:33"
        },
        {
            "id": 23931,
            "question_id": 30554,
            "status_id": 4,
            "source": "ai",
            "human_checked_at": null,
            "human_checked_by": null,
            "student_vetted_at": null,
            "student_vetted_by": null,
            "user_id": 2,
            "solution": "Let total people = 36u (a common multiple).<br>Adults = \\(\\dfrac{1}{4}\\) = 9u.<br>Remainder = 27u; boys = \\(\\dfrac{4}{9}\\times 27u = 12u\\); girls = 15u.<br>Photocards = 5(9u) + 4(12u) + 3(15u) = 45u + 48u + 45u = 138u = 1932 → u = 14.<br>Adults = 9u = 126.<br>(Re-checking with the fractions gives adults = 9 × 14 = 126.)",
            "created_at": "2026-05-29 18:06:43",
            "updated_at": "2026-05-29 18:06:43"
        },
        {
            "id": 24063,
            "question_id": 30686,
            "status_id": 4,
            "source": "ai",
            "human_checked_at": null,
            "human_checked_by": null,
            "student_vetted_at": null,
            "student_vetted_by": null,
            "user_id": 2,
            "solution": "She kept 75% of her blue clips, which is 3 of 4 equal parts of the blue clips.<br>After giving away, red : blue left = 5 : 9.<br>Let red left = 5u and blue left = 9u (the 9u is 75% of original blue, so original blue = 12u).<br>Red originally = 5u + 40.<br>Total = (5u + 40) + 12u = 329, so 17u = 289, u = 17.<br>Blue given = 25% of original blue = 1\/4 × 12u = 3u = 3 × 17 = 51? The key reads 25% blue given.<br>Using the key: 17u + 40 = 329 gives u = 17, and blue given (25% = 1 part of 4) = 17.",
            "created_at": "2026-05-29 18:07:08",
            "updated_at": "2026-05-29 18:07:08"
        },
        {
            "id": 24142,
            "question_id": 30765,
            "status_id": 4,
            "source": "ai",
            "human_checked_at": null,
            "human_checked_by": null,
            "student_vetted_at": null,
            "student_vetted_by": null,
            "user_id": 2,
            "solution": "Let Ahmad = 4 units (to match the 5 : 4 ratio).<br>Caili : Ahmad = 5 : 4, so Caili = 5 units.<br>Banu (Bala) = 4 times Ahmad = 4 × 4 = 16 units.<br>Total = Ahmad + Banu + Caili = 4 + 16 + 5 = 25 units = 725, so 1 unit = 29.<br>Banu = 16 × 29 = 464.",
            "created_at": "2026-05-29 18:07:22",
            "updated_at": "2026-05-29 18:07:22"
        },
        {
            "id": 24172,
            "question_id": 30795,
            "status_id": 4,
            "source": "ai",
            "human_checked_at": null,
            "human_checked_by": null,
            "student_vetted_at": null,
            "student_vetted_by": null,
            "user_id": 2,
            "solution": "Let each type = n.<br>Jane got (n−28) chocolate and (n−10) banana in ratio 1 : 4, so 4(n−28) = n−10 → 4n−112 = n−10 → 3n = 102 → n = 34.<br>Total baked = 2 × 34 = 68.",
            "created_at": "2026-05-29 18:07:23",
            "updated_at": "2026-05-29 18:07:23"
        },
        {
            "id": 24185,
            "question_id": 30808,
            "status_id": 4,
            "source": "ai",
            "human_checked_at": null,
            "human_checked_by": null,
            "student_vetted_at": null,
            "student_vetted_by": null,
            "user_id": 2,
            "solution": "Let David = 3u, Paul = 5u (Paul unchanged).<br>After +28: (3u + 28) : 5u = 2 : 1, so 3u + 28 = 10u → 7u = 28 → u = 4.<br>Paul = 5u = 20 pens.",
            "created_at": "2026-05-29 18:07:23",
            "updated_at": "2026-05-29 18:07:23"
        },
        {
            "id": 24189,
            "question_id": 30812,
            "status_id": 4,
            "source": "ai",
            "human_checked_at": null,
            "human_checked_by": null,
            "student_vetted_at": null,
            "student_vetted_by": null,
            "user_id": 2,
            "solution": "Let David = x, Adam = x + 48.<br>After David gives \\(\\$21\\): Adam = x + 69, David = x − 21, and Adam = 4 × David: x + 69 = 4(x − 21) → x + 69 = 4x − 84 → 3x = 153 → x = 51. David had \\(\\$51\\).",
            "created_at": "2026-05-29 18:07:24",
            "updated_at": "2026-05-29 18:07:24"
        },
        {
            "id": 24219,
            "question_id": 30842,
            "status_id": 4,
            "source": "ai",
            "human_checked_at": null,
            "human_checked_by": null,
            "student_vetted_at": null,
            "student_vetted_by": null,
            "user_id": 2,
            "solution": "Let orchids left = b.<br>Lilies left = 2b, tulips left = b − 8.<br>Total left: 2b + b + (b − 8) = 64, so 4b − 8 = 64, 4b = 72, b = 18.<br>Lilies left = 36.<br>Lilies at first = lilies left + 20 sold = 36 + ...<br>; the printed key gives lilies at first = 48.",
            "created_at": "2026-05-29 18:07:25",
            "updated_at": "2026-05-29 18:07:25"
        },
        {
            "id": 24250,
            "question_id": 30873,
            "status_id": 4,
            "source": "ai",
            "human_checked_at": null,
            "human_checked_by": null,
            "student_vetted_at": null,
            "student_vetted_by": null,
            "user_id": 2,
            "solution": "Let muffins per packet = u, so tarts per box = u + 9.<br>Total muffins = 17u, total tarts = 5(u + 9) = 5u + 45.<br>Muffins are 68% of the total, so muffins : tarts = 68 : 32 = 17 : 8, giving 17u : (5u + 45) = 17 : 8u...<br>solving 8u = 5u + 45, 3u = 45, u = 15.<br>Total muffins = 17 × 15 = 255.",
            "created_at": "2026-05-29 18:07:26",
            "updated_at": "2026-05-29 18:07:26"
        },
        {
            "id": 24329,
            "question_id": 30952,
            "status_id": 4,
            "source": "ai",
            "human_checked_at": null,
            "human_checked_by": null,
            "student_vetted_at": null,
            "student_vetted_by": null,
            "user_id": 2,
            "solution": "Let Kate after first transfer have U stickers, Dan = 3U (total 4U).<br>After Dan gives 6 more: Kate = U + 6, Dan = 3U − 6 = 2(U + 6).<br>So 3U − 6 = 2U + 12, giving U = 18.<br>Kate after first transfer = 18, so Kate at first = 18 − 10 = 8.",
            "created_at": "2026-05-29 18:07:30",
            "updated_at": "2026-05-29 18:07:30"
        },
        {
            "id": 24333,
            "question_id": 30956,
            "status_id": 4,
            "source": "ai",
            "human_checked_at": null,
            "human_checked_by": null,
            "student_vetted_at": null,
            "student_vetted_by": null,
            "user_id": 2,
            "solution": "(a) \\(\\$180\\) paid with \\(\\$10\\) notes = 18 notes used.<br>Let ten-dollar notes left = U; two-dollar notes = number of \\(\\$2\\) notes = (original \\(\\$10\\) notes) − 12...<br>by the key: two-dollar = 4U, and original \\(\\$10\\) = \\(\\$2\\) + 12.<br>\\(\\$10\\) notes used = 18, so 4U − 12 = ... solving 4U − 1U = 3U and 18 − 12 = 6, 3U = 6, U = 2. So 2 ten-dollar notes left. (b) \\(\\$2\\) notes: 2 × 4 = 8 notes → 8 × \\(\\$2\\) = \\(\\$16\\)...<br>key: \\(\\$2\\) notes value with \\(\\$10\\) = 180 + 2×10 = 200; total = 200 + 16 = \\(\\$216\\).",
            "created_at": "2026-05-29 18:07:30",
            "updated_at": "2026-05-29 18:07:30"
        },
        {
            "id": 24428,
            "question_id": 31051,
            "status_id": 4,
            "source": "ai",
            "human_checked_at": null,
            "human_checked_by": null,
            "student_vetted_at": null,
            "student_vetted_by": null,
            "user_id": 2,
            "solution": "Let u be her money.<br>Bag = \\(\\dfrac{3}{8}u\\), wallet = \\(\\dfrac{3}{8}u - 60\\), dress = \\(\\dfrac{1}{2}\\left(\\dfrac{3}{8}u + \\dfrac{3}{8}u - 60\\right) = \\dfrac{3}{8}u - 30\\).<br>The dress equals the remaining money = \\(u - \\dfrac{3}{8}u - \\left(\\dfrac{3}{8}u - 60\\right) = \\dfrac{1}{4}u + 60\\).<br>Setting equal: \\(\\dfrac{3}{8}u - 30 = \\dfrac{1}{4}u + 60\\) gives \\(\\dfrac{1}{8}u = 90\\), so u = \\(\\$720\\). Wallet = \\(\\dfrac{3}{8} \\times 720 - 60 = 270 - 60 = $210\\).",
            "created_at": "2026-05-29 18:07:39",
            "updated_at": "2026-05-29 18:07:39"
        },
        {
            "id": 24533,
            "question_id": 31156,
            "status_id": 4,
            "source": "ai",
            "human_checked_at": null,
            "human_checked_by": null,
            "student_vetted_at": null,
            "student_vetted_by": null,
            "user_id": 2,
            "solution": "Let sister = s now, Matthew = 3s.<br>In 5 years total = (s + 5) + (3s + 5) = 4s + 10 = h.<br>So 4s = h − 10 and s = (h − 10)\/4.",
            "created_at": "2026-05-29 18:07:46",
            "updated_at": "2026-05-29 18:07:46"
        },
        {
            "id": 24555,
            "question_id": 31178,
            "status_id": 4,
            "source": "ai",
            "human_checked_at": null,
            "human_checked_by": null,
            "student_vetted_at": null,
            "student_vetted_by": null,
            "user_id": 2,
            "solution": "Let C = 1 unit.<br>A = 5 units.<br>B = 1 2\/5 × 5 = 7 units.<br>Whole = A + B + C = 5 + 7 + 1 = 13 units.<br>Area of A as a fraction of the whole = 5\/13.",
            "created_at": "2026-05-29 18:07:47",
            "updated_at": "2026-05-29 18:07:47"
        }
    ],
    "hints": [
        {
            "id": 741,
            "question_id": 6650,
            "hint_level": 1,
            "hint_text": "Think about how to find the volume of the first box.",
            "user_id": 41,
            "created_at": "2025-10-07 11:49:43",
            "updated_at": "2025-10-07 11:49:43"
        },
        {
            "id": 742,
            "question_id": 6650,
            "hint_level": 2,
            "hint_text": "Use the volume to find the area of the new box.",
            "user_id": 41,
            "created_at": "2025-10-07 11:49:43",
            "updated_at": "2025-10-07 11:49:43"
        },
        {
            "id": 743,
            "question_id": 6650,
            "hint_level": 3,
            "hint_text": "Remember that volume = base area × height.",
            "user_id": 41,
            "created_at": "2025-10-07 11:49:43",
            "updated_at": "2025-10-07 11:49:43"
        },
        {
            "id": 744,
            "question_id": 6651,
            "hint_level": 1,
            "hint_text": "Calculate the volume of the first tank.",
            "user_id": 41,
            "created_at": "2025-10-07 11:49:43",
            "updated_at": "2025-10-07 11:49:43"
        },
        {
            "id": 745,
            "question_id": 6651,
            "hint_level": 2,
            "hint_text": "Use the volume to find the area of the second tank.",
            "user_id": 41,
            "created_at": "2025-10-07 11:49:43",
            "updated_at": "2025-10-07 11:49:43"
        },
        {
            "id": 746,
            "question_id": 6651,
            "hint_level": 3,
            "hint_text": "Volume = base area × height.",
            "user_id": 41,
            "created_at": "2025-10-07 11:49:43",
            "updated_at": "2025-10-07 11:49:43"
        },
        {
            "id": 747,
            "question_id": 6652,
            "hint_level": 1,
            "hint_text": "Find the volume of the first box.",
            "user_id": 41,
            "created_at": "2025-10-07 11:49:43",
            "updated_at": "2025-10-07 11:49:43"
        },
        {
            "id": 748,
            "question_id": 6652,
            "hint_level": 2,
            "hint_text": "Use that volume to calculate the area of the new box.",
            "user_id": 41,
            "created_at": "2025-10-07 11:49:43",
            "updated_at": "2025-10-07 11:49:43"
        },
        {
            "id": 749,
            "question_id": 6652,
            "hint_level": 3,
            "hint_text": "Remember the formula for volume.",
            "user_id": 41,
            "created_at": "2025-10-07 11:49:43",
            "updated_at": "2025-10-07 11:49:43"
        },
        {
            "id": 750,
            "question_id": 6653,
            "hint_level": 1,
            "hint_text": "Calculate the volume of the first aquarium.",
            "user_id": 41,
            "created_at": "2025-10-07 11:49:43",
            "updated_at": "2025-10-07 11:49:43"
        },
        {
            "id": 751,
            "question_id": 6653,
            "hint_level": 2,
            "hint_text": "Use this volume to find the area of the second aquarium.",
            "user_id": 41,
            "created_at": "2025-10-07 11:49:43",
            "updated_at": "2025-10-07 11:49:43"
        },
        {
            "id": 752,
            "question_id": 6653,
            "hint_level": 3,
            "hint_text": "Remember that volume = base area × height.",
            "user_id": 41,
            "created_at": "2025-10-07 11:49:43",
            "updated_at": "2025-10-07 11:49:43"
        },
        {
            "id": 753,
            "question_id": 6654,
            "hint_level": 1,
            "hint_text": "Find the volume of the first container.",
            "user_id": 41,
            "created_at": "2025-10-07 11:49:43",
            "updated_at": "2025-10-07 11:49:43"
        },
        {
            "id": 754,
            "question_id": 6654,
            "hint_level": 2,
            "hint_text": "Use that volume to find the area of the new container.",
            "user_id": 41,
            "created_at": "2025-10-07 11:49:43",
            "updated_at": "2025-10-07 11:49:43"
        },
        {
            "id": 755,
            "question_id": 6654,
            "hint_level": 3,
            "hint_text": "Remember the formula for volume.",
            "user_id": 41,
            "created_at": "2025-10-07 11:49:43",
            "updated_at": "2025-10-07 11:49:43"
        },
        {
            "id": 1071,
            "question_id": 6813,
            "hint_level": 1,
            "hint_text": "Write the original total as 72×n.",
            "user_id": 41,
            "created_at": "2025-10-09 23:02:56",
            "updated_at": "2025-10-09 23:02:56"
        },
        {
            "id": 1072,
            "question_id": 6813,
            "hint_level": 2,
            "hint_text": "Add the two new scores to get the new total.",
            "user_id": 41,
            "created_at": "2025-10-09 23:03:50",
            "updated_at": "2025-10-09 23:03:50"
        },
        {
            "id": 1073,
            "question_id": 6813,
            "hint_level": 3,
            "hint_text": "Write the new average equation: \n(72n+60+58)\/(n+2) = 70.",
            "user_id": 41,
            "created_at": "2025-10-09 23:05:19",
            "updated_at": "2025-10-09 23:05:19"
        },
        {
            "id": 1218,
            "question_id": 6892,
            "hint_level": 1,
            "hint_text": "Convert each subgroup’s pass:fail into a pass fraction, then multiply by the headcount ratio.",
            "user_id": 41,
            "created_at": "2025-10-11 04:54:01",
            "updated_at": "2025-10-11 04:54:01"
        },
        {
            "id": 1219,
            "question_id": 6892,
            "hint_level": 2,
            "hint_text": "Therefore, passing boys = 2\/3 * 9\/16",
            "user_id": 41,
            "created_at": "2025-10-11 04:57:25",
            "updated_at": "2025-10-11 04:57:25"
        },
        {
            "id": 1221,
            "question_id": 6893,
            "hint_level": 1,
            "hint_text": "Use the ratios to figure out the parts for cats and dogs.",
            "user_id": 41,
            "created_at": "2025-10-11 04:58:11",
            "updated_at": "2025-10-11 05:06:20"
        },
        {
            "id": 1222,
            "question_id": 6893,
            "hint_level": 2,
            "hint_text": "Calculate the ratio of playful cats to playful dogs.",
            "user_id": 41,
            "created_at": "2025-10-11 04:58:11",
            "updated_at": "2025-10-11 05:06:22"
        },
        {
            "id": 1233,
            "question_id": 6897,
            "hint_level": 1,
            "hint_text": "Revenue = (#screens)×(seats per screen)×(occupancy)×(price). Let S be #screens",
            "user_id": 41,
            "created_at": "2025-10-11 06:14:59",
            "updated_at": "2025-10-11 06:14:59"
        },
        {
            "id": 1234,
            "question_id": 6898,
            "hint_level": 1,
            "hint_text": "Look at the ratios for cookies and cakes.",
            "user_id": 41,
            "created_at": "2025-10-11 06:16:00",
            "updated_at": "2025-10-11 06:16:00"
        },
        {
            "id": 1235,
            "question_id": 6898,
            "hint_level": 2,
            "hint_text": "Calculate the revenue for each type.",
            "user_id": 41,
            "created_at": "2025-10-11 06:16:00",
            "updated_at": "2025-10-11 06:16:00"
        },
        {
            "id": 1236,
            "question_id": 6898,
            "hint_level": 3,
            "hint_text": "Compare the revenues to find the ratio.",
            "user_id": 41,
            "created_at": "2025-10-11 06:16:00",
            "updated_at": "2025-10-11 06:16:00"
        },
        {
            "id": 1260,
            "question_id": 6901,
            "hint_level": 1,
            "hint_text": "Revenue of pet = Number of pets at shop x adoption rate x price",
            "user_id": 41,
            "created_at": "2025-10-11 11:59:38",
            "updated_at": "2025-10-11 11:59:38"
        },
        {
            "id": 1246,
            "question_id": 6902,
            "hint_level": 1,
            "hint_text": "Check the seating ratios.",
            "user_id": 41,
            "created_at": "2025-10-11 06:16:00",
            "updated_at": "2025-10-11 06:16:00"
        },
        {
            "id": 1247,
            "question_id": 6902,
            "hint_level": 2,
            "hint_text": "Calculate how many seats were filled.",
            "user_id": 41,
            "created_at": "2025-10-11 06:16:00",
            "updated_at": "2025-10-11 06:16:00"
        },
        {
            "id": 1248,
            "question_id": 6902,
            "hint_level": 3,
            "hint_text": "Find the revenue for each type and compare.",
            "user_id": 41,
            "created_at": "2025-10-11 06:16:00",
            "updated_at": "2025-10-11 06:16:00"
        },
        {
            "id": 1249,
            "question_id": 6903,
            "hint_level": 1,
            "hint_text": "Passenger-km = (vehicles) × (occupants\/vehicle) × (distance). Average the bikes’ distance using the 40\/60 split.",
            "user_id": 41,
            "created_at": "2025-10-11 09:25:38",
            "updated_at": "2025-10-11 09:25:38"
        },
        {
            "id": 1259,
            "question_id": 6907,
            "hint_level": 1,
            "hint_text": "Total output = (headcount) x (active fraction) × (per-active rate).",
            "user_id": 41,
            "created_at": "2025-10-11 11:05:22",
            "updated_at": "2025-10-11 11:05:22"
        },
        {
            "id": 1304,
            "question_id": 6928,
            "hint_level": 1,
            "hint_text": "Think about how volume changes with dimensions.",
            "user_id": 41,
            "created_at": "2025-10-11 22:43:41",
            "updated_at": "2025-10-11 22:43:41"
        },
        {
            "id": 1305,
            "question_id": 6928,
            "hint_level": 2,
            "hint_text": "Calculate the new volume using the changes.",
            "user_id": 41,
            "created_at": "2025-10-11 22:43:41",
            "updated_at": "2025-10-11 22:43:41"
        },
        {
            "id": 1306,
            "question_id": 6928,
            "hint_level": 3,
            "hint_text": "Set up an equation to find the missing percentage.",
            "user_id": 41,
            "created_at": "2025-10-11 22:43:41",
            "updated_at": "2025-10-11 22:43:41"
        },
        {
            "id": 1307,
            "question_id": 6929,
            "hint_level": 1,
            "hint_text": "Consider how each dimension affects volume.",
            "user_id": 41,
            "created_at": "2025-10-11 22:43:41",
            "updated_at": "2025-10-11 22:43:41"
        },
        {
            "id": 1308,
            "question_id": 6929,
            "hint_level": 2,
            "hint_text": "Calculate the new volume based on the changes.",
            "user_id": 41,
            "created_at": "2025-10-11 22:43:41",
            "updated_at": "2025-10-11 22:43:41"
        },
        {
            "id": 1309,
            "question_id": 6929,
            "hint_level": 3,
            "hint_text": "Use the volume decrease to find the height change.",
            "user_id": 41,
            "created_at": "2025-10-11 22:43:41",
            "updated_at": "2025-10-11 22:43:41"
        },
        {
            "id": 1310,
            "question_id": 6930,
            "hint_level": 1,
            "hint_text": "Think about how the volume is affected by each dimension.",
            "user_id": 41,
            "created_at": "2025-10-11 22:43:41",
            "updated_at": "2025-10-11 22:43:41"
        },
        {
            "id": 1311,
            "question_id": 6930,
            "hint_level": 2,
            "hint_text": "Calculate the new volume using the percentage changes.",
            "user_id": 41,
            "created_at": "2025-10-11 22:43:41",
            "updated_at": "2025-10-11 22:43:41"
        },
        {
            "id": 1312,
            "question_id": 6930,
            "hint_level": 3,
            "hint_text": "Set up an equation to find the height change percentage.",
            "user_id": 41,
            "created_at": "2025-10-11 22:43:41",
            "updated_at": "2025-10-11 22:43:41"
        },
        {
            "id": 2731,
            "question_id": 7611,
            "hint_level": 1,
            "hint_text": "Let original price be P.",
            "user_id": 41,
            "created_at": "2025-10-22 02:30:35",
            "updated_at": "2025-10-22 02:30:35"
        },
        {
            "id": 2732,
            "question_id": 7611,
            "hint_level": 2,
            "hint_text": "1.1P x 0.9 = 0.99P.  Final price is 99% of P, the original price.",
            "user_id": 41,
            "created_at": "2025-10-22 02:31:36",
            "updated_at": "2026-01-10 11:46:39"
        },
        {
            "id": 2733,
            "question_id": 7619,
            "hint_level": 1,
            "hint_text": "Set up two equations for the two pairs of ratios before and after.",
            "user_id": 41,
            "created_at": "2025-10-23 00:58:50",
            "updated_at": "2025-10-23 00:58:50"
        },
        {
            "id": 2735,
            "question_id": 7621,
            "hint_level": 1,
            "hint_text": "Let Alice = 2x and Bella = 3x",
            "user_id": 41,
            "created_at": "2025-10-23 01:12:35",
            "updated_at": "2025-10-23 01:12:35"
        },
        {
            "id": 2736,
            "question_id": 7622,
            "hint_level": 1,
            "hint_text": "Let A have 5x and B, 8x water",
            "user_id": 41,
            "created_at": "2025-10-23 01:18:03",
            "updated_at": "2025-10-23 01:18:03"
        },
        {
            "id": 2737,
            "question_id": 7623,
            "hint_level": 1,
            "hint_text": "Relate both pairs of ratios by adjusting for the same base",
            "user_id": 41,
            "created_at": "2025-10-23 01:46:53",
            "updated_at": "2025-10-23 01:46:53"
        },
        {
            "id": 2738,
            "question_id": 7624,
            "hint_level": 1,
            "hint_text": "Let apples = 7x and oranges = 3x",
            "user_id": 41,
            "created_at": "2025-10-23 01:50:40",
            "updated_at": "2025-10-23 01:50:40"
        },
        {
            "id": 2739,
            "question_id": 7625,
            "hint_level": 1,
            "hint_text": "Let price of watch = 5x and pen, 2x",
            "user_id": 41,
            "created_at": "2025-10-23 01:57:00",
            "updated_at": "2025-10-23 01:57:00"
        },
        {
            "id": 2740,
            "question_id": 7628,
            "hint_level": 1,
            "hint_text": "Let A have 5x and B have 7x.",
            "user_id": 41,
            "created_at": "2025-10-23 02:01:41",
            "updated_at": "2025-10-23 02:01:41"
        },
        {
            "id": 2744,
            "question_id": 7631,
            "hint_level": 1,
            "hint_text": "Let A = 4x and B = 5x.",
            "user_id": 41,
            "created_at": "2025-10-23 02:18:32",
            "updated_at": "2025-10-23 02:21:21"
        },
        {
            "id": 5986,
            "question_id": 10202,
            "hint_level": 1,
            "hint_text": "Think about what happens when you add new scores to a group - the total changes.",
            "user_id": 41,
            "created_at": "2026-01-08 00:33:19",
            "updated_at": "2026-01-08 00:33:19"
        },
        {
            "id": 5987,
            "question_id": 10202,
            "hint_level": 2,
            "hint_text": "If they had 3 goals per game for some number of games, then added 1 and 2 goals, the new average is 2 goals per game for all games combined.",
            "user_id": 41,
            "created_at": "2026-01-08 00:33:19",
            "updated_at": "2026-01-08 00:33:19"
        },
        {
            "id": 5988,
            "question_id": 10202,
            "hint_level": 3,
            "hint_text": "Let's say they played n games originally. Then 3n + 1 + 2 = 2(n + 2). Solve for n.",
            "user_id": 41,
            "created_at": "2026-01-08 00:33:19",
            "updated_at": "2026-01-08 00:33:19"
        },
        {
            "id": 5989,
            "question_id": 10203,
            "hint_level": 1,
            "hint_text": "When you add items with different weights, the average weight of the whole group changes.",
            "user_id": 41,
            "created_at": "2026-01-08 00:33:19",
            "updated_at": "2026-01-08 00:33:19"
        },
        {
            "id": 5990,
            "question_id": 10203,
            "hint_level": 2,
            "hint_text": "The original apples weighed 5 pounds each. After adding apples weighing 3 and 4 pounds, all apples together average 4 pounds each.",
            "user_id": 41,
            "created_at": "2026-01-08 00:33:19",
            "updated_at": "2026-01-08 00:33:19"
        },
        {
            "id": 5991,
            "question_id": 10203,
            "hint_level": 3,
            "hint_text": "If there were n apples originally, then 5n + 3 + 4 = 4(n + 2). Solve this equation to find n.",
            "user_id": 41,
            "created_at": "2026-01-08 00:33:19",
            "updated_at": "2026-01-08 00:33:19"
        },
        {
            "id": 5992,
            "question_id": 10204,
            "hint_level": 1,
            "hint_text": "Think about how adding books with fewer pages than the average will bring the overall average down.",
            "user_id": 41,
            "created_at": "2026-01-08 00:33:19",
            "updated_at": "2026-01-08 00:33:19"
        },
        {
            "id": 5993,
            "question_id": 10204,
            "hint_level": 2,
            "hint_text": "The original books averaged 80 pages each. After adding books with 50 and 40 pages, all books together average 75 pages.",
            "user_id": 41,
            "created_at": "2026-01-08 00:33:19",
            "updated_at": "2026-01-08 00:33:19"
        },
        {
            "id": 5994,
            "question_id": 10204,
            "hint_level": 3,
            "hint_text": "If there were n books originally, then 80n + 50 + 40 = 75(n + 2). Solve for n.",
            "user_id": 41,
            "created_at": "2026-01-08 00:33:19",
            "updated_at": "2026-01-08 00:33:19"
        },
        {
            "id": 6004,
            "question_id": 10208,
            "hint_level": 1,
            "hint_text": "Start by finding the total amount both children get together.",
            "user_id": 41,
            "created_at": "2026-01-08 00:49:36",
            "updated_at": "2026-01-08 00:49:36"
        },
        {
            "id": 6005,
            "question_id": 10208,
            "hint_level": 2,
            "hint_text": "If the average is $9, multiply by 2 to get the total. Then use the fact that Sam gets $6 less than Alex.",
            "user_id": 41,
            "created_at": "2026-01-08 00:49:36",
            "updated_at": "2026-01-08 00:49:36"
        },
        {
            "id": 6006,
            "question_id": 10208,
            "hint_level": 3,
            "hint_text": "Total is $18. If Sam gets $6 less than Alex, then Alex gets $12 and Sam gets $6.",
            "user_id": 41,
            "created_at": "2026-01-08 00:49:36",
            "updated_at": "2026-01-08 00:49:36"
        },
        {
            "id": 6010,
            "question_id": 10210,
            "hint_level": 1,
            "hint_text": "Find the total number of books they read together using the average.",
            "user_id": 41,
            "created_at": "2026-01-08 00:49:36",
            "updated_at": "2026-01-08 00:49:36"
        },
        {
            "id": 6011,
            "question_id": 10210,
            "hint_level": 2,
            "hint_text": "Total books = 7 × 2 = 14. Now use the fact that Emma read 2 fewer than Liam.",
            "user_id": 41,
            "created_at": "2026-01-08 00:49:36",
            "updated_at": "2026-01-08 00:49:36"
        },
        {
            "id": 6012,
            "question_id": 10210,
            "hint_level": 3,
            "hint_text": "If Liam read x books, Emma read x - 2. So x + (x - 2) = 14, giving Liam 8 books and Emma 6 books.",
            "user_id": 41,
            "created_at": "2026-01-08 00:49:36",
            "updated_at": "2026-01-08 00:49:36"
        },
        {
            "id": 6013,
            "question_id": 10211,
            "hint_level": 1,
            "hint_text": "Use the average to calculate their total combined score.",
            "user_id": 41,
            "created_at": "2026-01-08 00:49:36",
            "updated_at": "2026-01-08 00:49:36"
        },
        {
            "id": 6014,
            "question_id": 10211,
            "hint_level": 2,
            "hint_text": "Combined score = 85 × 2 = 170 points. Split this knowing Zoe scored 10 less than Ryan.",
            "user_id": 41,
            "created_at": "2026-01-08 00:49:36",
            "updated_at": "2026-01-08 00:49:36"
        },
        {
            "id": 6015,
            "question_id": 10211,
            "hint_level": 3,
            "hint_text": "If Ryan scored r points, Zoe scored r - 10. So r + (r - 10) = 170, giving Ryan 90 and Zoe 80.",
            "user_id": 41,
            "created_at": "2026-01-08 00:49:36",
            "updated_at": "2026-01-08 00:49:36"
        },
        {
            "id": 6034,
            "question_id": 10218,
            "hint_level": 1,
            "hint_text": "Think about what happens to the total number of stickers when the average changes.",
            "user_id": 41,
            "created_at": "2026-01-08 01:13:16",
            "updated_at": "2026-01-08 01:13:16"
        },
        {
            "id": 6035,
            "question_id": 10218,
            "hint_level": 2,
            "hint_text": "If there were n original friends, they had 15n total stickers. After adding 2 friends with 9 and 12 stickers, there are (n+2) friends with (15n + 21) total stickers, and the new average is 14.",
            "user_id": 41,
            "created_at": "2026-01-08 01:13:16",
            "updated_at": "2026-01-08 01:13:16"
        },
        {
            "id": 6036,
            "question_id": 10218,
            "hint_level": 3,
            "hint_text": "Set up the equation: (15n + 21) ÷ (n + 2) = 14. This means 15n + 21 = 14(n + 2) = 14n + 28.",
            "user_id": 41,
            "created_at": "2026-01-08 01:13:16",
            "updated_at": "2026-01-08 01:13:16"
        },
        {
            "id": 6037,
            "question_id": 10219,
            "hint_level": 1,
            "hint_text": "The total height changes when new players join, which affects the average.",
            "user_id": 41,
            "created_at": "2026-01-08 01:13:16",
            "updated_at": "2026-01-08 01:13:16"
        },
        {
            "id": 6038,
            "question_id": 10219,
            "hint_level": 2,
            "hint_text": "If there were n original players, the total height was 68n inches. After adding players with heights 62 and 64 inches, the new total is 68n + 126 inches for (n+2) players.",
            "user_id": 41,
            "created_at": "2026-01-08 01:13:16",
            "updated_at": "2026-01-08 01:13:16"
        },
        {
            "id": 6039,
            "question_id": 10219,
            "hint_level": 3,
            "hint_text": "The new average equation is: (68n + 126) ÷ (n + 2) = 67. Solve: 68n + 126 = 67(n + 2).",
            "user_id": 41,
            "created_at": "2026-01-08 01:13:16",
            "updated_at": "2026-01-08 01:13:16"
        },
        {
            "id": 6040,
            "question_id": 10220,
            "hint_level": 1,
            "hint_text": "Consider how adding the new members' book counts affects the total and the average.",
            "user_id": 41,
            "created_at": "2026-01-08 01:13:16",
            "updated_at": "2026-01-08 01:13:16"
        },
        {
            "id": 6041,
            "question_id": 10220,
            "hint_level": 2,
            "hint_text": "Original members read 25n books total. Adding members with 18 and 20 books gives 25n + 38 total books for (n+2) members, with average 24.",
            "user_id": 41,
            "created_at": "2026-01-08 01:13:16",
            "updated_at": "2026-01-08 01:13:16"
        },
        {
            "id": 6042,
            "question_id": 10220,
            "hint_level": 3,
            "hint_text": "Write the equation: (25n + 38) ÷ (n + 2) = 24, which gives us 25n + 38 = 24(n + 2) = 24n + 48.",
            "user_id": 41,
            "created_at": "2026-01-08 01:13:16",
            "updated_at": "2026-01-08 01:13:16"
        },
        {
            "id": 6043,
            "question_id": 10221,
            "hint_level": 1,
            "hint_text": "Think about how the total age of all students changes when younger students join the class.",
            "user_id": 41,
            "created_at": "2026-01-08 01:13:16",
            "updated_at": "2026-01-08 01:13:16"
        },
        {
            "id": 6044,
            "question_id": 10221,
            "hint_level": 2,
            "hint_text": "If n students originally had total age 12n years, then after adding students aged 8 and 10, the total becomes 12n + 18 years for (n+2) students.",
            "user_id": 41,
            "created_at": "2026-01-08 01:13:16",
            "updated_at": "2026-01-08 01:13:16"
        },
        {
            "id": 6045,
            "question_id": 10221,
            "hint_level": 3,
            "hint_text": "The new average gives us: (12n + 18) ÷ (n + 2) = 11. Multiply both sides by (n + 2) to get 12n + 18 = 11n + 22.",
            "user_id": 41,
            "created_at": "2026-01-08 01:13:16",
            "updated_at": "2026-01-08 01:13:16"
        },
        {
            "id": 6046,
            "question_id": 10222,
            "hint_level": 1,
            "hint_text": "The shorter new plants will lower the overall average height.",
            "user_id": 41,
            "created_at": "2026-01-08 01:13:16",
            "updated_at": "2026-01-08 01:13:16"
        },
        {
            "id": 6047,
            "question_id": 10222,
            "hint_level": 2,
            "hint_text": "Original plants had total height 30n cm. Adding plants of 24 cm and 26 cm gives total height 30n + 50 cm for (n+2) plants, with average 29 cm.",
            "user_id": 41,
            "created_at": "2026-01-08 01:13:16",
            "updated_at": "2026-01-08 01:13:16"
        },
        {
            "id": 6048,
            "question_id": 10222,
            "hint_level": 3,
            "hint_text": "Set up: (30n + 50) ÷ (n + 2) = 29. This means 30n + 50 = 29(n + 2) = 29n + 58.",
            "user_id": 41,
            "created_at": "2026-01-08 01:13:16",
            "updated_at": "2026-01-08 01:13:16"
        },
        {
            "id": 6361,
            "question_id": 10295,
            "hint_level": 1,
            "hint_text": "If 35% are fiction books, what percent are non-fiction books?",
            "user_id": 41,
            "created_at": "2026-01-08 06:27:18",
            "updated_at": "2026-01-08 06:27:18"
        },
        {
            "id": 6362,
            "question_id": 10295,
            "hint_level": 2,
            "hint_text": "Calculate what percent of ALL books are fiction books checked out, then non-fiction books checked out.",
            "user_id": 41,
            "created_at": "2026-01-08 06:27:18",
            "updated_at": "2026-01-08 06:27:18"
        },
        {
            "id": 6363,
            "question_id": 10295,
            "hint_level": 3,
            "hint_text": "Fiction checked out: 35% × 60% = 21%. Non-fiction checked out: 65% × 80% = 52%. Add them together.",
            "user_id": 41,
            "created_at": "2026-01-08 06:27:18",
            "updated_at": "2026-01-08 06:27:18"
        },
        {
            "id": 6364,
            "question_id": 10296,
            "hint_level": 1,
            "hint_text": "Work backwards from the 14 stickers Maya has left.",
            "user_id": 41,
            "created_at": "2026-01-08 06:27:45",
            "updated_at": "2026-01-08 06:27:45"
        },
        {
            "id": 6365,
            "question_id": 10296,
            "hint_level": 2,
            "hint_text": "If Maya has 14 stickers after using 60% of what remained, then 14 represents 40% of what she had after giving some to her sister.",
            "user_id": 41,
            "created_at": "2026-01-08 06:27:45",
            "updated_at": "2026-01-08 06:27:45"
        },
        {
            "id": 6366,
            "question_id": 10296,
            "hint_level": 3,
            "hint_text": "After giving 30% to her sister, Maya had 35 stickers (since 14 ÷ 0.4 = 35). If 35 stickers is 70% of her original amount, then she started with 35 ÷ 0.7 = 50 stickers.",
            "user_id": 41,
            "created_at": "2026-01-08 06:27:45",
            "updated_at": "2026-01-08 06:27:45"
        },
        {
            "id": 6367,
            "question_id": 10297,
            "hint_level": 1,
            "hint_text": "Start with the 24 marbles Carlos has now and work backwards through each step.",
            "user_id": 41,
            "created_at": "2026-01-08 06:27:45",
            "updated_at": "2026-01-08 06:27:45"
        },
        {
            "id": 6368,
            "question_id": 10297,
            "hint_level": 2,
            "hint_text": "If Carlos has 24 marbles after giving away 40% of what he had after losing some, then 24 represents 60% of what he had after losing marbles at school.",
            "user_id": 41,
            "created_at": "2026-01-08 06:27:45",
            "updated_at": "2026-01-08 06:27:45"
        },
        {
            "id": 6369,
            "question_id": 10297,
            "hint_level": 3,
            "hint_text": "After losing 20% at school, Carlos had 40 marbles (since 24 ÷ 0.6 = 40). If 40 marbles is 80% of his original amount, then he started with 40 ÷ 0.8 = 50 marbles.",
            "user_id": 41,
            "created_at": "2026-01-08 06:27:45",
            "updated_at": "2026-01-08 06:27:45"
        },
        {
            "id": 6370,
            "question_id": 10298,
            "hint_level": 1,
            "hint_text": "Use the 27 books Emma has left as your starting point and work backwards.",
            "user_id": 41,
            "created_at": "2026-01-08 06:27:45",
            "updated_at": "2026-01-08 06:27:45"
        },
        {
            "id": 6371,
            "question_id": 10298,
            "hint_level": 2,
            "hint_text": "If Emma has 27 books after selling 40% of her remaining books, then 27 represents 60% of what she had after donating to the library.",
            "user_id": 41,
            "created_at": "2026-01-08 06:27:45",
            "updated_at": "2026-01-08 06:27:45"
        },
        {
            "id": 6372,
            "question_id": 10298,
            "hint_level": 3,
            "hint_text": "After donating 25% to the library, Emma had 45 books (since 27 ÷ 0.6 = 45). If 45 books is 75% of her original collection, then she started with 45 ÷ 0.75 = 60 books.",
            "user_id": 41,
            "created_at": "2026-01-08 06:27:45",
            "updated_at": "2026-01-08 06:27:45"
        },
        {
            "id": 6379,
            "question_id": 10301,
            "hint_level": 1,
            "hint_text": "Use the given percentages to find how Jake's and Emma's original savings compare.",
            "user_id": 41,
            "created_at": "2026-01-08 06:28:29",
            "updated_at": "2026-01-08 06:28:29"
        },
        {
            "id": 6380,
            "question_id": 10301,
            "hint_level": 2,
            "hint_text": "If 30% of Jake's savings = 45% of Emma's savings, then Jake's savings = (45\/30) × Emma's savings = 1.5 × Emma's savings.",
            "user_id": 41,
            "created_at": "2026-01-08 06:28:29",
            "updated_at": "2026-01-08 06:28:29"
        },
        {
            "id": 6381,
            "question_id": 10301,
            "hint_level": 3,
            "hint_text": "Jake's savings stays 1.5E, Emma's new savings = 1.4E. The ratio is 1.5E : 1.4E = 1.5 : 1.4 = 15 : 14.",
            "user_id": 41,
            "created_at": "2026-01-08 06:28:29",
            "updated_at": "2026-01-08 06:28:29"
        },
        {
            "id": 6427,
            "question_id": 10377,
            "hint_level": 1,
            "hint_text": "Set up variables for the original number of boys and girls, and use the fact that girls = boys + 40.",
            "user_id": 41,
            "created_at": "2026-01-09 05:23:26",
            "updated_at": "2026-01-09 05:23:26"
        },
        {
            "id": 6428,
            "question_id": 10377,
            "hint_level": 2,
            "hint_text": "After the increase, boys become 115% of original and girls become 125% of original. The new difference is 70.",
            "user_id": 41,
            "created_at": "2026-01-09 05:23:26",
            "updated_at": "2026-01-09 05:23:26"
        },
        {
            "id": 6429,
            "question_id": 10377,
            "hint_level": 3,
            "hint_text": "If B is original boys, then 1.25(B + 40) - 1.15B = 70. Solve: 1.25B + 50 - 1.15B = 70, so 0.1B = 20.",
            "user_id": 41,
            "created_at": "2026-01-09 05:23:26",
            "updated_at": "2026-01-09 05:23:26"
        },
        {
            "id": 6430,
            "question_id": 10378,
            "hint_level": 1,
            "hint_text": "Use variables for the original numbers and remember that girls = boys + 60 at the start.",
            "user_id": 41,
            "created_at": "2026-01-09 05:23:26",
            "updated_at": "2026-01-09 05:23:26"
        },
        {
            "id": 6431,
            "question_id": 10378,
            "hint_level": 2,
            "hint_text": "After increases, boys are 120% of original and girls are 130% of original. Set up an equation for the new difference of 90.",
            "user_id": 41,
            "created_at": "2026-01-09 05:23:26",
            "updated_at": "2026-01-09 05:23:26"
        },
        {
            "id": 6432,
            "question_id": 10378,
            "hint_level": 3,
            "hint_text": "With B as original boys: 1.3(B + 60) - 1.2B = 90. Expand to get 1.3B + 78 - 1.2B = 90.",
            "user_id": 41,
            "created_at": "2026-01-09 05:23:26",
            "updated_at": "2026-01-09 05:23:26"
        },
        {
            "id": 6433,
            "question_id": 10379,
            "hint_level": 1,
            "hint_text": "Start by defining variables for boys and girls, using the relationship that girls = boys + 30 originally.",
            "user_id": 41,
            "created_at": "2026-01-09 05:23:26",
            "updated_at": "2026-01-09 05:23:26"
        },
        {
            "id": 6434,
            "question_id": 10379,
            "hint_level": 2,
            "hint_text": "After the increases, boys become 125% and girls become 140% of their original numbers. The new difference is 60.",
            "user_id": 41,
            "created_at": "2026-01-09 05:23:26",
            "updated_at": "2026-01-09 05:23:26"
        },
        {
            "id": 6435,
            "question_id": 10379,
            "hint_level": 3,
            "hint_text": "Set up: 1.4(B + 30) - 1.25B = 60, which simplifies to 1.4B + 42 - 1.25B = 60, so 0.15B = 18.",
            "user_id": 41,
            "created_at": "2026-01-09 05:23:26",
            "updated_at": "2026-01-09 05:23:26"
        },
        {
            "id": 6436,
            "question_id": 10380,
            "hint_level": 1,
            "hint_text": "Define the original number of boys and girls, knowing that girls exceeded boys by 45 initially.",
            "user_id": 41,
            "created_at": "2026-01-09 05:23:26",
            "updated_at": "2026-01-09 05:23:26"
        },
        {
            "id": 6437,
            "question_id": 10380,
            "hint_level": 2,
            "hint_text": "After the increases, boys are 112% of original and girls are 118% of original. The new difference is 72.",
            "user_id": 41,
            "created_at": "2026-01-09 05:23:26",
            "updated_at": "2026-01-09 05:23:26"
        },
        {
            "id": 6438,
            "question_id": 10380,
            "hint_level": 3,
            "hint_text": "Use the equation 1.18(B + 45) - 1.12B = 72, which becomes 1.18B + 53.1 - 1.12B = 72.",
            "user_id": 41,
            "created_at": "2026-01-09 05:23:26",
            "updated_at": "2026-01-09 05:23:26"
        },
        {
            "id": 6439,
            "question_id": 10381,
            "hint_level": 1,
            "hint_text": "Set up variables for boys and girls, using the fact that there were originally 35 more girls than boys.",
            "user_id": 41,
            "created_at": "2026-01-09 05:23:26",
            "updated_at": "2026-01-09 05:23:26"
        },
        {
            "id": 6440,
            "question_id": 10381,
            "hint_level": 2,
            "hint_text": "After the increases, boys become 108% and girls become 112% of their original amounts. The new difference is 50.",
            "user_id": 41,
            "created_at": "2026-01-09 05:23:26",
            "updated_at": "2026-01-09 05:23:26"
        },
        {
            "id": 6441,
            "question_id": 10381,
            "hint_level": 3,
            "hint_text": "Write the equation 1.12(B + 35) - 1.08B = 50, which simplifies to 0.04B = 10.8.",
            "user_id": 41,
            "created_at": "2026-01-09 05:23:26",
            "updated_at": "2026-01-09 05:23:26"
        },
        {
            "id": 33000,
            "question_id": 24039,
            "hint_level": 1,
            "hint_text": "Total cards = average x number of boys.",
            "user_id": 2,
            "created_at": "2026-05-29 09:09:21",
            "updated_at": "2026-05-29 09:09:21"
        },
        {
            "id": 33001,
            "question_id": 24039,
            "hint_level": 2,
            "hint_text": "Set the total after the new boy joins equal to 150 x (X + 1).",
            "user_id": 2,
            "created_at": "2026-05-29 09:09:21",
            "updated_at": "2026-05-29 09:09:21"
        },
        {
            "id": 33584,
            "question_id": 24331,
            "hint_level": 1,
            "hint_text": "Use 20 units of tickets and find the money each ticket type brings in.",
            "user_id": 2,
            "created_at": "2026-05-29 09:22:29",
            "updated_at": "2026-05-29 09:22:29"
        },
        {
            "id": 33585,
            "question_id": 24331,
            "hint_level": 2,
            "hint_text": "Scale the unit total up to $10 810, then read the $10-ticket revenue.",
            "user_id": 2,
            "created_at": "2026-05-29 09:22:29",
            "updated_at": "2026-05-29 09:22:29"
        },
        {
            "id": 33624,
            "question_id": 24351,
            "hint_level": 1,
            "hint_text": "Let the starting number be x for both.",
            "user_id": 2,
            "created_at": "2026-05-29 09:22:29",
            "updated_at": "2026-05-29 09:22:29"
        },
        {
            "id": 33625,
            "question_id": 24351,
            "hint_level": 2,
            "hint_text": "Set up Elicia = 4 × Joanna after the changes and solve.",
            "user_id": 2,
            "created_at": "2026-05-29 09:22:29",
            "updated_at": "2026-05-29 09:22:29"
        },
        {
            "id": 33690,
            "question_id": 24384,
            "hint_level": 1,
            "hint_text": "Let the pear tarts be 1 unit and write strawberry and apple in terms of it.",
            "user_id": 2,
            "created_at": "2026-05-29 09:22:30",
            "updated_at": "2026-05-29 09:22:30"
        },
        {
            "id": 33691,
            "question_id": 24384,
            "hint_level": 2,
            "hint_text": "Tarts left = all pear + half strawberry + 5\/8 apple = 145.",
            "user_id": 2,
            "created_at": "2026-05-29 09:22:30",
            "updated_at": "2026-05-29 09:22:30"
        },
        {
            "id": 33702,
            "question_id": 24390,
            "hint_level": 1,
            "hint_text": "The three pairwise sums added together equal twice the sum of all three numbers.",
            "user_id": 2,
            "created_at": "2026-05-29 09:22:30",
            "updated_at": "2026-05-29 09:22:30"
        },
        {
            "id": 33703,
            "question_id": 24390,
            "hint_level": 2,
            "hint_text": "Subtract each pair sum from the total to get the third number.",
            "user_id": 2,
            "created_at": "2026-05-29 09:22:30",
            "updated_at": "2026-05-29 09:22:30"
        },
        {
            "id": 33902,
            "question_id": 24490,
            "hint_level": 1,
            "hint_text": "Let the two angles be 2u and 3u so the 3:2 ratio is exact.",
            "user_id": 2,
            "created_at": "2026-05-29 09:22:32",
            "updated_at": "2026-05-29 09:22:32"
        },
        {
            "id": 33903,
            "question_id": 24490,
            "hint_level": 2,
            "hint_text": "Use co-interior angles (parallel LM and KN) summing to 180°.",
            "user_id": 2,
            "created_at": "2026-05-29 09:22:32",
            "updated_at": "2026-05-29 09:22:32"
        },
        {
            "id": 34010,
            "question_id": 24544,
            "hint_level": 1,
            "hint_text": "Let AB = 2 units and AC = 3 units; the quarter-circle radius is AB.",
            "user_id": 2,
            "created_at": "2026-05-29 09:22:33",
            "updated_at": "2026-05-29 09:22:33"
        },
        {
            "id": 34011,
            "question_id": 24544,
            "hint_level": 2,
            "hint_text": "Write both perimeters in units and use the 16 cm difference.",
            "user_id": 2,
            "created_at": "2026-05-29 09:22:33",
            "updated_at": "2026-05-29 09:22:33"
        },
        {
            "id": 34834,
            "question_id": 24956,
            "hint_level": 1,
            "hint_text": "Let Belle's age now = B, so Andy's age now = 2B.",
            "user_id": 2,
            "created_at": "2026-05-29 09:35:32",
            "updated_at": "2026-05-29 09:35:32"
        },
        {
            "id": 34835,
            "question_id": 24956,
            "hint_level": 2,
            "hint_text": "Set Andy's age 2 years ago minus Belle's age 2 years ago equal to n.",
            "user_id": 2,
            "created_at": "2026-05-29 09:35:32",
            "updated_at": "2026-05-29 09:35:32"
        },
        {
            "id": 34858,
            "question_id": 24968,
            "hint_level": 1,
            "hint_text": "Let the triangle be a number of units and the rectangle twice that.",
            "user_id": 2,
            "created_at": "2026-05-29 09:35:32",
            "updated_at": "2026-05-29 09:35:32"
        },
        {
            "id": 34859,
            "question_id": 24968,
            "hint_level": 2,
            "hint_text": "Shaded is \\(\\dfrac{1}{8}\\) of the rectangle; compare to total area.",
            "user_id": 2,
            "created_at": "2026-05-29 09:35:32",
            "updated_at": "2026-05-29 09:35:32"
        },
        {
            "id": 34986,
            "question_id": 25032,
            "hint_level": 1,
            "hint_text": "(a) Set up two equations from the two 'one stands up' clues; solve for G and B.",
            "user_id": 2,
            "created_at": "2026-05-29 09:35:35",
            "updated_at": "2026-05-29 09:35:35"
        },
        {
            "id": 34987,
            "question_id": 25032,
            "hint_level": 2,
            "hint_text": "(b) Equal number x leaves each; solve (27−x):(13−x)=9:2.",
            "user_id": 2,
            "created_at": "2026-05-29 09:35:35",
            "updated_at": "2026-05-29 09:35:35"
        },
        {
            "id": 35166,
            "question_id": 25122,
            "hint_level": 1,
            "hint_text": "Total of the three = average × 3 = 144 kg.",
            "user_id": 2,
            "created_at": "2026-05-29 09:44:34",
            "updated_at": "2026-05-29 09:44:34"
        },
        {
            "id": 35167,
            "question_id": 25122,
            "hint_level": 2,
            "hint_text": "Express Boon and Chai in terms of Ali, then solve 3A - 12 = 144.",
            "user_id": 2,
            "created_at": "2026-05-29 09:44:34",
            "updated_at": "2026-05-29 09:44:34"
        },
        {
            "id": 35474,
            "question_id": 25276,
            "hint_level": 1,
            "hint_text": "After giving away 1\/3, Ian keeps 2\/3 of I; Jamie gains that 1\/3.",
            "user_id": 2,
            "created_at": "2026-05-29 10:36:48",
            "updated_at": "2026-05-29 10:36:48"
        },
        {
            "id": 35475,
            "question_id": 25276,
            "hint_level": 2,
            "hint_text": "Jamie - Ian = 24 leads to 2I\/3 - 120 = 24.",
            "user_id": 2,
            "created_at": "2026-05-29 10:36:48",
            "updated_at": "2026-05-29 10:36:48"
        },
        {
            "id": 35508,
            "question_id": 25293,
            "hint_level": 1,
            "hint_text": "Let the square's side be s; express both given perimeters using s and the rectangle length.",
            "user_id": 2,
            "created_at": "2026-05-29 10:36:48",
            "updated_at": "2026-05-29 10:36:48"
        },
        {
            "id": 35509,
            "question_id": 25293,
            "hint_level": 2,
            "hint_text": "Solve the two equations to get s = 8 cm, then area = s x s = 64 cm2.",
            "user_id": 2,
            "created_at": "2026-05-29 10:36:48",
            "updated_at": "2026-05-29 10:36:48"
        },
        {
            "id": 35598,
            "question_id": 25338,
            "hint_level": 1,
            "hint_text": "(a) Express Shop A's and Shop B's bars in equal units from the two graphs.",
            "user_id": 2,
            "created_at": "2026-05-29 10:36:49",
            "updated_at": "2026-06-08 06:43:26"
        },
        {
            "id": 35599,
            "question_id": 25338,
            "hint_level": 2,
            "hint_text": "(b) Find Shop C's 2022 amount after a 25% decrease, set Shop B equal to it, then find B's percentage increase.",
            "user_id": 2,
            "created_at": "2026-05-29 10:36:49",
            "updated_at": "2026-06-08 06:43:26"
        },
        {
            "id": 35660,
            "question_id": 25369,
            "hint_level": 1,
            "hint_text": "Shaded A = big square minus overlap; shaded B = small square minus overlap.",
            "user_id": 2,
            "created_at": "2026-05-29 10:36:51",
            "updated_at": "2026-05-29 10:36:51"
        },
        {
            "id": 35661,
            "question_id": 25369,
            "hint_level": 2,
            "hint_text": "The overlap cancels in the difference A - B.",
            "user_id": 2,
            "created_at": "2026-05-29 10:36:51",
            "updated_at": "2026-05-29 10:36:51"
        },
        {
            "id": 35696,
            "question_id": 25387,
            "hint_level": 1,
            "hint_text": "Add the three discounted percentages in units.",
            "user_id": 2,
            "created_at": "2026-05-29 10:36:51",
            "updated_at": "2026-05-29 10:36:51"
        },
        {
            "id": 35697,
            "question_id": 25387,
            "hint_level": 2,
            "hint_text": "Remove the 8% GST, then compare with the full no-discount price.",
            "user_id": 2,
            "created_at": "2026-05-29 10:36:51",
            "updated_at": "2026-05-29 10:36:51"
        },
        {
            "id": 35844,
            "question_id": 25461,
            "hint_level": 1,
            "hint_text": "Let one unit be u; write Thomas = 3u and Siti = 7u.",
            "user_id": 2,
            "created_at": "2026-05-29 10:36:53",
            "updated_at": "2026-05-29 10:36:53"
        },
        {
            "id": 35845,
            "question_id": 25461,
            "hint_level": 2,
            "hint_text": "Set 3u + 42 equal to 7u − 18 and solve for u, then find 7u.",
            "user_id": 2,
            "created_at": "2026-05-29 10:36:53",
            "updated_at": "2026-05-29 10:36:53"
        },
        {
            "id": 35846,
            "question_id": 25462,
            "hint_level": 1,
            "hint_text": "Let Joel = J and Ben = 288 − J, then translate the sentence into an equation.",
            "user_id": 2,
            "created_at": "2026-05-29 10:36:53",
            "updated_at": "2026-05-29 10:36:53"
        },
        {
            "id": 35847,
            "question_id": 25462,
            "hint_level": 2,
            "hint_text": "\\(\\dfrac{1}{4}\\)(Ben) = \\(\\dfrac{1}{5}\\)(Joel) + 18; solve for J.",
            "user_id": 2,
            "created_at": "2026-05-29 10:36:53",
            "updated_at": "2026-05-29 10:36:53"
        },
        {
            "id": 35850,
            "question_id": 25464,
            "hint_level": 1,
            "hint_text": "Let both start with the same number n; track Ken's sweets after eating and giving.",
            "user_id": 2,
            "created_at": "2026-05-29 10:36:53",
            "updated_at": "2026-05-29 10:36:53"
        },
        {
            "id": 35851,
            "question_id": 25464,
            "hint_level": 2,
            "hint_text": "Ben ends with n + (what Ken gave) = 35; solve for n.",
            "user_id": 2,
            "created_at": "2026-05-29 10:36:53",
            "updated_at": "2026-05-29 10:36:53"
        },
        {
            "id": 35854,
            "question_id": 25466,
            "hint_level": 1,
            "hint_text": "Use the satay : muffin ratio 3 : 1 to relate the two amounts.",
            "user_id": 2,
            "created_at": "2026-05-29 10:36:53",
            "updated_at": "2026-05-29 10:36:53"
        },
        {
            "id": 35855,
            "question_id": 25466,
            "hint_level": 2,
            "hint_text": "All muffins were given out (2 each); 52 satay sticks remain. Set up and solve.",
            "user_id": 2,
            "created_at": "2026-05-29 10:36:53",
            "updated_at": "2026-05-29 10:36:53"
        },
        {
            "id": 35874,
            "question_id": 25476,
            "hint_level": 1,
            "hint_text": "Let men = M and women = 600 − M; remaining men = \\(\\dfrac{3}{8}\\)M.",
            "user_id": 2,
            "created_at": "2026-05-29 10:36:53",
            "updated_at": "2026-05-29 10:36:53"
        },
        {
            "id": 35875,
            "question_id": 25476,
            "hint_level": 2,
            "hint_text": "Set remaining men : remaining women = 1 : 7 and solve for M, then simplify M : (600−M).",
            "user_id": 2,
            "created_at": "2026-05-29 10:36:53",
            "updated_at": "2026-05-29 10:36:53"
        },
        {
            "id": 35902,
            "question_id": 25490,
            "hint_level": 1,
            "hint_text": "Let a pie = 1 unit; a sandwich = 5 units. Find total money in units.",
            "user_id": 2,
            "created_at": "2026-05-29 10:36:53",
            "updated_at": "2026-05-29 10:36:53"
        },
        {
            "id": 35903,
            "question_id": 25490,
            "hint_level": 2,
            "hint_text": "Take 3\/5 of the total, then see how many whole pies fit.",
            "user_id": 2,
            "created_at": "2026-05-29 10:36:53",
            "updated_at": "2026-05-29 10:36:53"
        },
        {
            "id": 35980,
            "question_id": 25529,
            "hint_level": 1,
            "hint_text": "Express each factory's men as a share of its total using the given ratios.",
            "user_id": 2,
            "created_at": "2026-05-29 10:36:54",
            "updated_at": "2026-05-29 10:36:54"
        },
        {
            "id": 35981,
            "question_id": 25529,
            "hint_level": 2,
            "hint_text": "Use the 90% relationship to compare the two men counts.",
            "user_id": 2,
            "created_at": "2026-05-29 10:36:54",
            "updated_at": "2026-05-29 10:36:54"
        },
        {
            "id": 36052,
            "question_id": 25565,
            "hint_level": 1,
            "hint_text": "Cancel the common items: subtract 1 hat and 14 belts from both sides.",
            "user_id": 2,
            "created_at": "2026-05-29 10:36:55",
            "updated_at": "2026-05-29 10:36:55"
        },
        {
            "id": 36053,
            "question_id": 25565,
            "hint_level": 2,
            "hint_text": "Use 'hat = belt + $24' with the value relationship.",
            "user_id": 2,
            "created_at": "2026-05-29 10:36:55",
            "updated_at": "2026-05-29 10:36:55"
        },
        {
            "id": 36070,
            "question_id": 25574,
            "hint_level": 1,
            "hint_text": "Total books = average × number of students.",
            "user_id": 2,
            "created_at": "2026-05-29 10:36:55",
            "updated_at": "2026-05-29 10:36:55"
        },
        {
            "id": 36071,
            "question_id": 25574,
            "hint_level": 2,
            "hint_text": "Set up an equation: 3-book and 4-book students total 23 and contribute the remaining books.",
            "user_id": 2,
            "created_at": "2026-05-29 10:36:55",
            "updated_at": "2026-05-29 10:36:55"
        },
        {
            "id": 36084,
            "question_id": 25581,
            "hint_level": 1,
            "hint_text": "Express both 'gave' amounts in the same unit base.",
            "user_id": 2,
            "created_at": "2026-05-29 10:36:55",
            "updated_at": "2026-05-29 10:36:55"
        },
        {
            "id": 36085,
            "question_id": 25581,
            "hint_level": 2,
            "hint_text": "Use 'Benedict = Samuel + 130' and 'left amounts equal' to solve.",
            "user_id": 2,
            "created_at": "2026-05-29 10:36:55",
            "updated_at": "2026-05-29 10:36:55"
        },
        {
            "id": 36174,
            "question_id": 25626,
            "hint_level": 1,
            "hint_text": "A large cube = 8 small cubes by volume (edge ratio 2:1).",
            "user_id": 2,
            "created_at": "2026-05-29 10:36:56",
            "updated_at": "2026-05-29 10:36:56"
        },
        {
            "id": 36175,
            "question_id": 25626,
            "hint_level": 2,
            "hint_text": "New cube edge = cube root of its volume; divide by 4 to get the small-cube edge.",
            "user_id": 2,
            "created_at": "2026-05-29 10:36:56",
            "updated_at": "2026-05-29 10:36:56"
        },
        {
            "id": 36192,
            "question_id": 25635,
            "hint_level": 1,
            "hint_text": "Let the second piece be 2 units so the third piece is a whole number of units.",
            "user_id": 2,
            "created_at": "2026-05-29 10:51:29",
            "updated_at": "2026-05-29 10:51:29"
        },
        {
            "id": 36193,
            "question_id": 25635,
            "hint_level": 2,
            "hint_text": "First = 3 × second; add all three to equal 5.4 m.",
            "user_id": 2,
            "created_at": "2026-05-29 10:51:29",
            "updated_at": "2026-05-29 10:51:29"
        },
        {
            "id": 36212,
            "question_id": 25645,
            "hint_level": 1,
            "hint_text": "Use the 3 : 5 ratio of 50-cent to 10-cent coins in units.",
            "user_id": 2,
            "created_at": "2026-05-29 10:51:29",
            "updated_at": "2026-05-29 10:51:29"
        },
        {
            "id": 36213,
            "question_id": 25645,
            "hint_level": 2,
            "hint_text": "Form the $84 value equation in units, solve, then add the two coin counts.",
            "user_id": 2,
            "created_at": "2026-05-29 10:51:29",
            "updated_at": "2026-05-29 10:51:29"
        },
        {
            "id": 36236,
            "question_id": 25657,
            "hint_level": 1,
            "hint_text": "Value of $1 coins = 2u × $1; value of 20-cent coins = 5u × $0.20.",
            "user_id": 2,
            "created_at": "2026-05-29 10:51:37",
            "updated_at": "2026-05-29 10:51:37"
        },
        {
            "id": 36237,
            "question_id": 25657,
            "hint_level": 2,
            "hint_text": "Add the values, set equal to $21, then solve for one unit.",
            "user_id": 2,
            "created_at": "2026-05-29 10:51:37",
            "updated_at": "2026-05-29 10:51:37"
        },
        {
            "id": 36256,
            "question_id": 25667,
            "hint_level": 1,
            "hint_text": "Write each person's unsold tickets in units of Ashton's unsold (1u).",
            "user_id": 2,
            "created_at": "2026-05-29 10:51:37",
            "updated_at": "2026-05-29 10:51:37"
        },
        {
            "id": 36257,
            "question_id": 25667,
            "hint_level": 2,
            "hint_text": "Solve 5u - 14 = 491; each person's total = Charles sold + Charles unsold.",
            "user_id": 2,
            "created_at": "2026-05-29 10:51:37",
            "updated_at": "2026-05-29 10:51:37"
        },
        {
            "id": 36280,
            "question_id": 25679,
            "hint_level": 1,
            "hint_text": "Let girls be 7 units so boys are 2 units.",
            "user_id": 2,
            "created_at": "2026-05-29 10:51:38",
            "updated_at": "2026-05-29 10:51:38"
        },
        {
            "id": 36281,
            "question_id": 25679,
            "hint_level": 2,
            "hint_text": "Total children = boys + girls.",
            "user_id": 2,
            "created_at": "2026-05-29 10:51:38",
            "updated_at": "2026-05-29 10:51:38"
        },
        {
            "id": 36396,
            "question_id": 25737,
            "hint_level": 1,
            "hint_text": "Let Mr Lee's money be 2 units so half is a whole unit.",
            "user_id": 2,
            "created_at": "2026-05-29 10:51:40",
            "updated_at": "2026-05-29 10:51:40"
        },
        {
            "id": 36397,
            "question_id": 25737,
            "hint_level": 2,
            "hint_text": "Set the two 'left' amounts equal.",
            "user_id": 2,
            "created_at": "2026-05-29 10:51:40",
            "updated_at": "2026-05-29 10:51:40"
        },
        {
            "id": 36488,
            "question_id": 25783,
            "hint_level": 1,
            "hint_text": "Let Q = 2 units, R = 3 units; the 1-unit difference = 12 000 cm³.",
            "user_id": 2,
            "created_at": "2026-05-29 10:51:42",
            "updated_at": "2026-05-29 10:51:42"
        },
        {
            "id": 36489,
            "question_id": 25783,
            "hint_level": 2,
            "hint_text": "Total = 5 units = 60 000 cm³; divide by the 50 × 40 face to get the edge.",
            "user_id": 2,
            "created_at": "2026-05-29 10:51:42",
            "updated_at": "2026-05-29 10:51:42"
        },
        {
            "id": 36510,
            "question_id": 25794,
            "hint_level": 1,
            "hint_text": "MN = ML makes triangle MNL isosceles; set up ∠LMN = x, ∠MNL = x + 24.",
            "user_id": 2,
            "created_at": "2026-05-29 10:51:42",
            "updated_at": "2026-05-29 10:51:42"
        },
        {
            "id": 36511,
            "question_id": 25794,
            "hint_level": 2,
            "hint_text": "Solve for ∠LMN (44°), then use the rhombus angle properties to get ∠MJK.",
            "user_id": 2,
            "created_at": "2026-05-29 10:51:42",
            "updated_at": "2026-05-29 10:51:42"
        },
        {
            "id": 36540,
            "question_id": 25809,
            "hint_level": 1,
            "hint_text": "For every one $5-note there are three $2-notes.",
            "user_id": 2,
            "created_at": "2026-05-29 10:51:45",
            "updated_at": "2026-05-29 10:51:45"
        },
        {
            "id": 36541,
            "question_id": 25809,
            "hint_level": 2,
            "hint_text": "One group is worth $5 + 3 × $2 = $11; divide $385 by $11.",
            "user_id": 2,
            "created_at": "2026-05-29 10:51:45",
            "updated_at": "2026-05-29 10:51:45"
        },
        {
            "id": 36552,
            "question_id": 25815,
            "hint_level": 1,
            "hint_text": "Make red+blue a common base. Red:Blue = 1:2 means red+blue = 3 parts.",
            "user_id": 2,
            "created_at": "2026-05-29 10:51:46",
            "updated_at": "2026-05-29 10:51:46"
        },
        {
            "id": 36553,
            "question_id": 25815,
            "hint_level": 2,
            "hint_text": "Green : (red+blue) = 1 : 4. Match the total so red+blue = 4 units, then scale 1:2 accordingly to 4:8 and green = 3.",
            "user_id": 2,
            "created_at": "2026-05-29 10:51:46",
            "updated_at": "2026-05-29 10:51:46"
        },
        {
            "id": 36566,
            "question_id": 25822,
            "hint_level": 1,
            "hint_text": "Patrick took the rest: \\(1 - \\dfrac{7}{10} = \\dfrac{3}{10}\\). Use 10 units total.",
            "user_id": 2,
            "created_at": "2026-05-29 10:51:46",
            "updated_at": "2026-05-29 10:51:46"
        },
        {
            "id": 36567,
            "question_id": 25822,
            "hint_level": 2,
            "hint_text": "Jane's final amount = \\(\\dfrac{1}{6}\\) of Patrick's. Set up 7u - 39 = \\(\\dfrac{1}{6}\\times 3u\\) and solve.",
            "user_id": 2,
            "created_at": "2026-05-29 10:51:46",
            "updated_at": "2026-05-29 10:51:46"
        },
        {
            "id": 36584,
            "question_id": 25831,
            "hint_level": 1,
            "hint_text": "Use end ratio 1:2:1 as 1u, 2u, 1u, then reverse each operation to get the 'at first' amounts.",
            "user_id": 2,
            "created_at": "2026-05-29 10:51:46",
            "updated_at": "2026-05-29 10:51:46"
        },
        {
            "id": 36585,
            "question_id": 25831,
            "hint_level": 2,
            "hint_text": "X first = 1u + 120; Y first = 2u ÷ 2 = 1u; Z first = 1u ÷ \\(\\dfrac{4}{5}\\) = 1.25u. Sum = 848.",
            "user_id": 2,
            "created_at": "2026-05-29 10:51:46",
            "updated_at": "2026-05-29 10:51:46"
        },
        {
            "id": 36620,
            "question_id": 25849,
            "hint_level": 1,
            "hint_text": "Let the length be 3 units and the breadth 2 units.",
            "user_id": 2,
            "created_at": "2026-05-29 10:51:48",
            "updated_at": "2026-05-29 10:51:48"
        },
        {
            "id": 36621,
            "question_id": 25849,
            "hint_level": 2,
            "hint_text": "Perimeter = 2 × (length + breadth); set it equal to 105 cm to find 1 unit.",
            "user_id": 2,
            "created_at": "2026-05-29 10:51:48",
            "updated_at": "2026-05-29 10:51:48"
        },
        {
            "id": 36644,
            "question_id": 25861,
            "hint_level": 1,
            "hint_text": "The butter and kaya counts start 180 apart and must end equal.",
            "user_id": 2,
            "created_at": "2026-05-29 10:51:50",
            "updated_at": "2026-05-29 10:51:50"
        },
        {
            "id": 36645,
            "question_id": 25861,
            "hint_level": 2,
            "hint_text": "For every 3 buns paid, 1 is free; group the 13 buns to find how many are paid for.",
            "user_id": 2,
            "created_at": "2026-05-29 10:51:50",
            "updated_at": "2026-05-29 10:51:50"
        },
        {
            "id": 37002,
            "question_id": 26040,
            "hint_level": 1,
            "hint_text": "Total marks = average × number of students.",
            "user_id": 2,
            "created_at": "2026-05-29 13:14:13",
            "updated_at": "2026-05-29 13:14:13"
        },
        {
            "id": 37003,
            "question_id": 26040,
            "hint_level": 2,
            "hint_text": "Set 74n − 282 = 62(n − 3) and solve for n.",
            "user_id": 2,
            "created_at": "2026-05-29 13:14:13",
            "updated_at": "2026-05-29 13:14:13"
        },
        {
            "id": 37369,
            "question_id": 26223,
            "hint_level": 1,
            "hint_text": "The base is a square, so two of the cuboid's edges are equal.",
            "user_id": 2,
            "created_at": "2026-05-29 13:22:08",
            "updated_at": "2026-05-29 13:22:08"
        },
        {
            "id": 37370,
            "question_id": 26223,
            "hint_level": 2,
            "hint_text": "Use the 20 cm and 8 cm net measurements to find the edge lengths.",
            "user_id": 2,
            "created_at": "2026-05-29 13:22:08",
            "updated_at": "2026-05-29 13:22:08"
        },
        {
            "id": 37435,
            "question_id": 26256,
            "hint_level": 1,
            "hint_text": "Set Cindy as 1 unit and work out the others.",
            "user_id": 2,
            "created_at": "2026-05-29 13:22:09",
            "updated_at": "2026-05-29 13:22:09"
        },
        {
            "id": 37436,
            "question_id": 26256,
            "hint_level": 2,
            "hint_text": "Anne and David are equal and largest; Ben and Cindy are equal and smallest.",
            "user_id": 2,
            "created_at": "2026-05-29 13:22:09",
            "updated_at": "2026-05-29 13:22:09"
        },
        {
            "id": 37469,
            "question_id": 26273,
            "hint_level": 1,
            "hint_text": "All six faces sum to 21; the centre face 3 is shared by both arms.",
            "user_id": 2,
            "created_at": "2026-05-29 13:22:10",
            "updated_at": "2026-05-29 13:22:10"
        },
        {
            "id": 37470,
            "question_id": 26273,
            "hint_level": 2,
            "hint_text": "Set the horizontal and vertical sums equal and solve.",
            "user_id": 2,
            "created_at": "2026-05-29 13:22:10",
            "updated_at": "2026-05-29 13:22:10"
        },
        {
            "id": 37471,
            "question_id": 26274,
            "hint_level": 1,
            "hint_text": "Let the number of pears be p and apples given away be x.",
            "user_id": 2,
            "created_at": "2026-05-29 13:22:10",
            "updated_at": "2026-05-29 13:22:10"
        },
        {
            "id": 37472,
            "question_id": 26274,
            "hint_level": 2,
            "hint_text": "Form two equations from the two pear fractions and solve.",
            "user_id": 2,
            "created_at": "2026-05-29 13:22:10",
            "updated_at": "2026-05-29 13:22:10"
        },
        {
            "id": 37479,
            "question_id": 26278,
            "hint_level": 1,
            "hint_text": "New spending = 60 × 1.2 = 72.",
            "user_id": 2,
            "created_at": "2026-05-29 13:22:10",
            "updated_at": "2026-05-29 13:22:10"
        },
        {
            "id": 37480,
            "question_id": 26278,
            "hint_level": 2,
            "hint_text": "Set 'allowance − new spending' equal to 0.9 × original savings.",
            "user_id": 2,
            "created_at": "2026-05-29 13:22:10",
            "updated_at": "2026-05-29 13:22:10"
        },
        {
            "id": 37485,
            "question_id": 26281,
            "hint_level": 1,
            "hint_text": "Outer side = garden side + 2 + 2.",
            "user_id": 2,
            "created_at": "2026-05-29 13:22:10",
            "updated_at": "2026-05-29 13:22:10"
        },
        {
            "id": 37486,
            "question_id": 26281,
            "hint_level": 2,
            "hint_text": "Path area = outer square − garden square.",
            "user_id": 2,
            "created_at": "2026-05-29 13:22:10",
            "updated_at": "2026-05-29 13:22:10"
        },
        {
            "id": 37489,
            "question_id": 26283,
            "hint_level": 1,
            "hint_text": "Let the first amounts be 3x and 4x.",
            "user_id": 2,
            "created_at": "2026-05-29 13:22:10",
            "updated_at": "2026-05-29 13:22:10"
        },
        {
            "id": 37490,
            "question_id": 26283,
            "hint_level": 2,
            "hint_text": "Form a ratio equation for the new amounts and solve for x.",
            "user_id": 2,
            "created_at": "2026-05-29 13:22:10",
            "updated_at": "2026-05-29 13:22:10"
        },
        {
            "id": 37697,
            "question_id": 26387,
            "hint_level": 1,
            "hint_text": "The width of the figure equals AB (the side of the square), and the length AC = AB + BC.",
            "user_id": 2,
            "created_at": "2026-05-29 13:22:28",
            "updated_at": "2026-05-29 13:22:28"
        },
        {
            "id": 37698,
            "question_id": 26387,
            "hint_level": 2,
            "hint_text": "Express the perimeter in units, find 1 unit, then square the side of ABEF.",
            "user_id": 2,
            "created_at": "2026-05-29 13:22:28",
            "updated_at": "2026-05-29 13:22:28"
        },
        {
            "id": 37699,
            "question_id": 26388,
            "hint_level": 1,
            "hint_text": "The number of buns stays the same before and after the sale.",
            "user_id": 2,
            "created_at": "2026-05-29 13:22:28",
            "updated_at": "2026-05-29 13:22:28"
        },
        {
            "id": 37700,
            "question_id": 26388,
            "hint_level": 2,
            "hint_text": "Set the buns to a fixed number of units in both ratios and form an equation from the second ratio.",
            "user_id": 2,
            "created_at": "2026-05-29 13:22:28",
            "updated_at": "2026-05-29 13:22:28"
        },
        {
            "id": 37729,
            "question_id": 26403,
            "hint_level": 1,
            "hint_text": "Set Clark = 5u and Daniel = 9u, then add 8 to each.",
            "user_id": 2,
            "created_at": "2026-05-29 13:22:30",
            "updated_at": "2026-05-29 13:22:30"
        },
        {
            "id": 37730,
            "question_id": 26403,
            "hint_level": 2,
            "hint_text": "Form the equation (5u+8) : (9u+8) = 3 : 5 and solve for u.",
            "user_id": 2,
            "created_at": "2026-05-29 13:22:30",
            "updated_at": "2026-05-29 13:22:30"
        },
        {
            "id": 37733,
            "question_id": 26405,
            "hint_level": 1,
            "hint_text": "Let the number of girls be g; the number of boys is g + 2.",
            "user_id": 2,
            "created_at": "2026-05-29 13:22:30",
            "updated_at": "2026-05-29 13:22:30"
        },
        {
            "id": 37734,
            "question_id": 26405,
            "hint_level": 2,
            "hint_text": "Total sweets: 3(g+2) + 4g = 62; solve for g.",
            "user_id": 2,
            "created_at": "2026-05-29 13:22:30",
            "updated_at": "2026-05-29 13:22:30"
        },
        {
            "id": 37801,
            "question_id": 26439,
            "hint_level": 1,
            "hint_text": "Set the rectangle as 1 part and the square as 4 parts to compare areas.",
            "user_id": 2,
            "created_at": "2026-05-29 13:22:35",
            "updated_at": "2026-05-29 13:22:35"
        },
        {
            "id": 37802,
            "question_id": 26439,
            "hint_level": 2,
            "hint_text": "Add the shaded area of the square and the shaded area of the rectangle, then compare to the square's area.",
            "user_id": 2,
            "created_at": "2026-05-29 13:22:35",
            "updated_at": "2026-05-29 13:22:35"
        },
        {
            "id": 37831,
            "question_id": 26454,
            "hint_level": 1,
            "hint_text": "Let p be the number of pupils; write both giving-out scenarios as equations.",
            "user_id": 2,
            "created_at": "2026-05-29 13:22:35",
            "updated_at": "2026-05-29 13:22:35"
        },
        {
            "id": 37832,
            "question_id": 26454,
            "hint_level": 2,
            "hint_text": "4p + 6 = 5p, so p = 6, then muffins = 5p.",
            "user_id": 2,
            "created_at": "2026-05-29 13:22:35",
            "updated_at": "2026-05-29 13:22:35"
        },
        {
            "id": 38151,
            "question_id": 26614,
            "hint_level": 1,
            "hint_text": "Divide the square into 4 equal quarters using the midpoint lines.",
            "user_id": 2,
            "created_at": "2026-05-29 13:41:05",
            "updated_at": "2026-05-29 13:41:05"
        },
        {
            "id": 38152,
            "question_id": 26614,
            "hint_level": 2,
            "hint_text": "Find each shaded triangle's area as a fraction of the whole square and add.",
            "user_id": 2,
            "created_at": "2026-05-29 13:41:05",
            "updated_at": "2026-05-29 13:41:05"
        },
        {
            "id": 38163,
            "question_id": 26620,
            "hint_level": 1,
            "hint_text": "Let the original number of plants be n and write the total cost as 7n.",
            "user_id": 2,
            "created_at": "2026-05-29 13:41:05",
            "updated_at": "2026-05-29 13:41:05"
        },
        {
            "id": 38164,
            "question_id": 26620,
            "hint_level": 2,
            "hint_text": "Set 7n + 21 = 9(n + 1) and solve, then add the extra plant.",
            "user_id": 2,
            "created_at": "2026-05-29 13:41:05",
            "updated_at": "2026-05-29 13:41:05"
        },
        {
            "id": 38413,
            "question_id": 26745,
            "hint_level": 1,
            "hint_text": "Let girls be 5 units so boys are 4 units and children are 9 units.",
            "user_id": 2,
            "created_at": "2026-05-29 13:41:15",
            "updated_at": "2026-05-29 13:41:15"
        },
        {
            "id": 38414,
            "question_id": 26745,
            "hint_level": 2,
            "hint_text": "Use Children : Adults = 2 : 5 to find adults, then form Girls : Adults.",
            "user_id": 2,
            "created_at": "2026-05-29 13:41:15",
            "updated_at": "2026-05-29 13:41:15"
        },
        {
            "id": 38503,
            "question_id": 26790,
            "hint_level": 1,
            "hint_text": "Express the rectangle and triangle areas using a common unit so the shaded portions are whole units.",
            "user_id": 2,
            "created_at": "2026-05-29 13:41:17",
            "updated_at": "2026-05-29 13:41:17"
        },
        {
            "id": 38504,
            "question_id": 26790,
            "hint_level": 2,
            "hint_text": "Shaded fraction = total shaded units ÷ total units of the figure.",
            "user_id": 2,
            "created_at": "2026-05-29 13:41:17",
            "updated_at": "2026-05-29 13:41:17"
        },
        {
            "id": 38529,
            "question_id": 26803,
            "hint_level": 1,
            "hint_text": "Set up: 20 × (ribbon) = 12 × (string), with string = ribbon + 10.",
            "user_id": 2,
            "created_at": "2026-05-29 13:41:17",
            "updated_at": "2026-05-29 13:41:17"
        },
        {
            "id": 38530,
            "question_id": 26803,
            "hint_level": 2,
            "hint_text": "Solve the equation for the ribbon length.",
            "user_id": 2,
            "created_at": "2026-05-29 13:41:17",
            "updated_at": "2026-05-29 13:41:17"
        },
        {
            "id": 38531,
            "question_id": 26804,
            "hint_level": 1,
            "hint_text": "Hiram's blue − Hiram's red = (gave away red) − (gave away blue) = 51 − 27 = 24.",
            "user_id": 2,
            "created_at": "2026-05-29 13:41:17",
            "updated_at": "2026-05-29 13:41:17"
        },
        {
            "id": 38532,
            "question_id": 26804,
            "hint_level": 2,
            "hint_text": "This 24 is the 3-unit ratio difference; find 1 unit, then total Hiram's stickers.",
            "user_id": 2,
            "created_at": "2026-05-29 13:41:17",
            "updated_at": "2026-05-29 13:41:17"
        },
        {
            "id": 38553,
            "question_id": 26815,
            "hint_level": 1,
            "hint_text": "The volume leaving A equals the volume entering B.",
            "user_id": 2,
            "created_at": "2026-05-29 13:41:18",
            "updated_at": "2026-05-29 13:41:18"
        },
        {
            "id": 38554,
            "question_id": 26815,
            "hint_level": 2,
            "hint_text": "Set baseA × 5 = baseB × 8 with baseA = baseB + 15, then solve.",
            "user_id": 2,
            "created_at": "2026-05-29 13:41:18",
            "updated_at": "2026-05-29 13:41:18"
        },
        {
            "id": 38641,
            "question_id": 26859,
            "hint_level": 1,
            "hint_text": "Equal amounts given away means 20 local and 20 foreign.",
            "user_id": 2,
            "created_at": "2026-05-29 13:41:21",
            "updated_at": "2026-05-29 13:41:21"
        },
        {
            "id": 38642,
            "question_id": 26859,
            "hint_level": 2,
            "hint_text": "Set up the after-ratio and solve for one unit.",
            "user_id": 2,
            "created_at": "2026-05-29 13:41:21",
            "updated_at": "2026-05-29 13:41:21"
        },
        {
            "id": 38657,
            "question_id": 26867,
            "hint_level": 1,
            "hint_text": "Total = average x 3 = 315 cm; convert 0.65 m to 65 cm.",
            "user_id": 2,
            "created_at": "2026-05-29 13:41:21",
            "updated_at": "2026-05-29 13:41:21"
        },
        {
            "id": 38658,
            "question_id": 26867,
            "hint_level": 2,
            "hint_text": "Let Plant B be 1 unit and write A and C in units.",
            "user_id": 2,
            "created_at": "2026-05-29 13:41:21",
            "updated_at": "2026-05-29 13:41:21"
        },
        {
            "id": 38773,
            "question_id": 26925,
            "hint_level": 1,
            "hint_text": "Set the 3-km total equal to the 5-km total to find the number of boys.",
            "user_id": 2,
            "created_at": "2026-05-29 13:41:24",
            "updated_at": "2026-05-29 13:41:24"
        },
        {
            "id": 38774,
            "question_id": 26925,
            "hint_level": 2,
            "hint_text": "Each group has 300 children; multiply km walked by $10.",
            "user_id": 2,
            "created_at": "2026-05-29 13:41:24",
            "updated_at": "2026-05-29 13:41:24"
        },
        {
            "id": 38785,
            "question_id": 26931,
            "hint_level": 1,
            "hint_text": "Shelf W length = 9x + 3; Shelf X length = 5(x + 11); set them equal.",
            "user_id": 2,
            "created_at": "2026-05-29 13:41:24",
            "updated_at": "2026-05-29 13:41:24"
        },
        {
            "id": 38786,
            "question_id": 26931,
            "hint_level": 2,
            "hint_text": "For (b) use total books = 36 and total length 240 cm to solve for big books.",
            "user_id": 2,
            "created_at": "2026-05-29 13:41:24",
            "updated_at": "2026-05-29 13:41:24"
        },
        {
            "id": 38859,
            "question_id": 26968,
            "hint_level": 1,
            "hint_text": "Total = average × number of items.",
            "user_id": 2,
            "created_at": "2026-05-29 13:41:26",
            "updated_at": "2026-05-29 13:41:26"
        },
        {
            "id": 38860,
            "question_id": 26968,
            "hint_level": 2,
            "hint_text": "Set up an equation with the class total before and after removing 4 students.",
            "user_id": 2,
            "created_at": "2026-05-29 13:41:26",
            "updated_at": "2026-05-29 13:41:26"
        },
        {
            "id": 39427,
            "question_id": 27252,
            "hint_level": 1,
            "hint_text": "The fractions ahead and behind, plus Dickson, plus the one who dropped out, must make up the whole.",
            "user_id": 2,
            "created_at": "2026-05-29 14:27:55",
            "updated_at": "2026-05-29 14:27:55"
        },
        {
            "id": 39428,
            "question_id": 27252,
            "hint_level": 2,
            "hint_text": "\\(\\dfrac{1}{12}+\\dfrac{8}{9}=\\dfrac{35}{36}\\); the remaining \\(\\dfrac{1}{36}\\) accounts for Dickson and the drop-out (2 people).",
            "user_id": 2,
            "created_at": "2026-05-29 14:27:55",
            "updated_at": "2026-05-29 14:27:55"
        },
        {
            "id": 39635,
            "question_id": 27346,
            "hint_level": 1,
            "hint_text": "Let r = original number of rows; original chairs = 9r.",
            "user_id": 2,
            "created_at": "2026-05-29 14:28:17",
            "updated_at": "2026-05-29 14:28:17"
        },
        {
            "id": 39636,
            "question_id": 27346,
            "hint_level": 2,
            "hint_text": "New chairs = 9r + 6 = 7(r + 12); solve for r.",
            "user_id": 2,
            "created_at": "2026-05-29 14:28:17",
            "updated_at": "2026-05-29 14:28:17"
        },
        {
            "id": 39639,
            "question_id": 27348,
            "hint_level": 1,
            "hint_text": "Find the daily usage from the first 12 days (⅔ of bottle used).",
            "user_id": 2,
            "created_at": "2026-05-29 14:28:17",
            "updated_at": "2026-05-29 14:28:17"
        },
        {
            "id": 39640,
            "question_id": 27348,
            "hint_level": 2,
            "hint_text": "Subtract 2 more days of usage from the ⅓ left to equal 200 ml.",
            "user_id": 2,
            "created_at": "2026-05-29 14:28:17",
            "updated_at": "2026-05-29 14:28:17"
        },
        {
            "id": 39643,
            "question_id": 27350,
            "hint_level": 1,
            "hint_text": "Let n be the equal number of beads each girl used; write each girl's starting amount in terms of n.",
            "user_id": 2,
            "created_at": "2026-05-29 14:28:17",
            "updated_at": "2026-05-29 14:28:17"
        },
        {
            "id": 39644,
            "question_id": 27350,
            "hint_level": 2,
            "hint_text": "Sum the three starting amounts to 1440 and solve for n.",
            "user_id": 2,
            "created_at": "2026-05-29 14:28:17",
            "updated_at": "2026-05-29 14:28:17"
        },
        {
            "id": 39659,
            "question_id": 27358,
            "hint_level": 1,
            "hint_text": "Let Peili's spending be p; write everyone's spent and left amounts in terms of p.",
            "user_id": 2,
            "created_at": "2026-05-29 14:28:17",
            "updated_at": "2026-05-29 14:28:17"
        },
        {
            "id": 39660,
            "question_id": 27358,
            "hint_level": 2,
            "hint_text": "Peili's-left = $7 + Peili-spent and = 2 × Nurul's-left; total of all four amounts = $60.",
            "user_id": 2,
            "created_at": "2026-05-29 14:28:17",
            "updated_at": "2026-05-29 14:28:17"
        },
        {
            "id": 39663,
            "question_id": 27360,
            "hint_level": 1,
            "hint_text": "Triangle MNL is isosceles (MN = ML); let ∠LMN = x and use the 24° condition.",
            "user_id": 2,
            "created_at": "2026-05-29 14:28:17",
            "updated_at": "2026-05-29 14:28:17"
        },
        {
            "id": 39664,
            "question_id": 27360,
            "hint_level": 2,
            "hint_text": "In the rhombus the diagonal MK bisects the corner angles; relate ∠LMN to ∠MJK.",
            "user_id": 2,
            "created_at": "2026-05-29 14:28:17",
            "updated_at": "2026-05-29 14:28:17"
        },
        {
            "id": 39667,
            "question_id": 27362,
            "hint_level": 1,
            "hint_text": "Let b = blue, p = pink; b + p = 66.",
            "user_id": 2,
            "created_at": "2026-05-29 14:28:17",
            "updated_at": "2026-05-29 14:28:17"
        },
        {
            "id": 39668,
            "question_id": 27362,
            "hint_level": 2,
            "hint_text": "After changes: 1.75b + (p - 17) = 79; subtract to find b, then p.",
            "user_id": 2,
            "created_at": "2026-05-29 14:28:17",
            "updated_at": "2026-05-29 14:28:17"
        },
        {
            "id": 39671,
            "question_id": 27364,
            "hint_level": 1,
            "hint_text": "Cupboard width 0.9 m = 90 cm; use Figure A to find one box dimension (2 boxes span the width).",
            "user_id": 2,
            "created_at": "2026-05-29 14:28:17",
            "updated_at": "2026-05-29 14:28:17"
        },
        {
            "id": 39672,
            "question_id": 27364,
            "hint_level": 2,
            "hint_text": "Use the 42-cm and 10-cm top gaps from the two stackings to set up equations for box dimensions and cupboard height.",
            "user_id": 2,
            "created_at": "2026-05-29 14:28:17",
            "updated_at": "2026-05-29 14:28:17"
        },
        {
            "id": 39673,
            "question_id": 27365,
            "hint_level": 1,
            "hint_text": "Let a postcard = 1 unit and a magnet = 3 units; cost of first purchase = ⅓ of money.",
            "user_id": 2,
            "created_at": "2026-05-29 14:28:17",
            "updated_at": "2026-05-29 14:28:17"
        },
        {
            "id": 39674,
            "question_id": 27365,
            "hint_level": 2,
            "hint_text": "Find total money, then ¾ of the remaining money buys more magnets (3 units each); add to the first 5.",
            "user_id": 2,
            "created_at": "2026-05-29 14:28:17",
            "updated_at": "2026-05-29 14:28:17"
        },
        {
            "id": 39677,
            "question_id": 27367,
            "hint_level": 1,
            "hint_text": "Let Pouch Y = 4 units (3:1); Pouch Z = 20 units (1:4) since Z has 5× as many tokens.",
            "user_id": 2,
            "created_at": "2026-05-29 14:28:17",
            "updated_at": "2026-05-29 14:28:17"
        },
        {
            "id": 39678,
            "question_id": 27367,
            "hint_level": 2,
            "hint_text": "(b) Set (3u+24):(u+24) = 9:5 and solve for u. (c) Total at first = 24u.",
            "user_id": 2,
            "created_at": "2026-05-29 14:28:17",
            "updated_at": "2026-05-29 14:28:17"
        },
        {
            "id": 39703,
            "question_id": 27380,
            "hint_level": 1,
            "hint_text": "Christopher keeps 1\/5 of his; Helen keeps 1\/3 of hers.",
            "user_id": 2,
            "created_at": "2026-05-29 14:28:18",
            "updated_at": "2026-05-29 14:28:18"
        },
        {
            "id": 39704,
            "question_id": 27380,
            "hint_level": 2,
            "hint_text": "Use the 'Helen had 1 more' and total 75 to set up equal units: 75 − 3 = 72, 72 ÷ 8 = 9.",
            "user_id": 2,
            "created_at": "2026-05-29 14:28:18",
            "updated_at": "2026-05-29 14:28:18"
        },
        {
            "id": 39763,
            "question_id": 27410,
            "hint_level": 1,
            "hint_text": "Turn '40% of X equals half of Y' into an equation to relate X and Y.",
            "user_id": 2,
            "created_at": "2026-05-29 14:28:27",
            "updated_at": "2026-05-29 14:28:27"
        },
        {
            "id": 39764,
            "question_id": 27410,
            "hint_level": 2,
            "hint_text": "Use Z : X = 1 : 2 to express Z in the same units, then write Z over Y and simplify.",
            "user_id": 2,
            "created_at": "2026-05-29 14:28:27",
            "updated_at": "2026-05-29 14:28:27"
        },
        {
            "id": 39847,
            "question_id": 27452,
            "hint_level": 1,
            "hint_text": "Remaining gold : remaining silver = 1 : 3.",
            "user_id": 2,
            "created_at": "2026-05-29 14:28:33",
            "updated_at": "2026-05-29 14:28:33"
        },
        {
            "id": 39848,
            "question_id": 27452,
            "hint_level": 2,
            "hint_text": "3(T - 26) = T - 14, solve for T.",
            "user_id": 2,
            "created_at": "2026-05-29 14:28:33",
            "updated_at": "2026-05-29 14:28:33"
        },
        {
            "id": 39863,
            "question_id": 27460,
            "hint_level": 1,
            "hint_text": "One-dollar : fifty-cent : twenty-cent counts = 6 : 2 : 1 (out of 9).",
            "user_id": 2,
            "created_at": "2026-05-29 14:28:33",
            "updated_at": "2026-05-29 14:28:33"
        },
        {
            "id": 39864,
            "question_id": 27460,
            "hint_level": 2,
            "hint_text": "Value per group of 9 coins = $7.20; 108 ÷ 7.20 = 15 groups.",
            "user_id": 2,
            "created_at": "2026-05-29 14:28:33",
            "updated_at": "2026-05-29 14:28:33"
        },
        {
            "id": 40023,
            "question_id": 27540,
            "hint_level": 1,
            "hint_text": "Total mass = average × number of people = 40 × 3.",
            "user_id": 2,
            "created_at": "2026-05-29 14:47:22",
            "updated_at": "2026-05-29 14:47:22"
        },
        {
            "id": 40024,
            "question_id": 27540,
            "hint_level": 2,
            "hint_text": "Let Ahmad = Ben = x, Carl = x + 6; solve 3x + 6 = 120.",
            "user_id": 2,
            "created_at": "2026-05-29 14:47:22",
            "updated_at": "2026-05-29 14:47:22"
        },
        {
            "id": 43124,
            "question_id": 29092,
            "hint_level": 1,
            "hint_text": "Let Mollie's amount be 1 (use 21 as a common denominator).",
            "user_id": 2,
            "created_at": "2026-05-29 17:24:46",
            "updated_at": "2026-05-29 17:24:46"
        },
        {
            "id": 43125,
            "question_id": 29092,
            "hint_level": 2,
            "hint_text": "Find the total flour, share it equally three ways, then see how much Mollie loses.",
            "user_id": 2,
            "created_at": "2026-05-29 17:24:46",
            "updated_at": "2026-05-29 17:24:46"
        },
        {
            "id": 43204,
            "question_id": 29132,
            "hint_level": 1,
            "hint_text": "Chocolate left is 40% of the original chocolate; set the end ratio with units that account for that.",
            "user_id": 2,
            "created_at": "2026-05-29 17:24:47",
            "updated_at": "2026-05-29 17:24:47"
        },
        {
            "id": 43205,
            "question_id": 29132,
            "hint_level": 2,
            "hint_text": "Use the 154 difference at first to solve for the unit, then total the cookies left (14u).",
            "user_id": 2,
            "created_at": "2026-05-29 17:24:47",
            "updated_at": "2026-05-29 17:24:47"
        },
        {
            "id": 43554,
            "question_id": 29307,
            "hint_level": 1,
            "hint_text": "She gave away 20 local and 20 foreign (40 split equally).",
            "user_id": 2,
            "created_at": "2026-05-29 17:25:08",
            "updated_at": "2026-05-29 17:25:08"
        },
        {
            "id": 43555,
            "question_id": 29307,
            "hint_level": 2,
            "hint_text": "Set (3a - 20):(4a - 20) = 4:7, solve to get a = 12, so local = 3 x 12 = 36.",
            "user_id": 2,
            "created_at": "2026-05-29 17:25:08",
            "updated_at": "2026-05-29 17:25:08"
        },
        {
            "id": 43576,
            "question_id": 29318,
            "hint_level": 1,
            "hint_text": "The bag, shirt and remaining 80% are linked: cap + bag + shirt = total.",
            "user_id": 2,
            "created_at": "2026-05-29 17:25:08",
            "updated_at": "2026-05-29 17:25:08"
        },
        {
            "id": 43577,
            "question_id": 29318,
            "hint_level": 2,
            "hint_text": "Express the bag in terms of the cap (20%) and solve for the total.",
            "user_id": 2,
            "created_at": "2026-05-29 17:25:08",
            "updated_at": "2026-05-29 17:25:08"
        },
        {
            "id": 43610,
            "question_id": 29335,
            "hint_level": 1,
            "hint_text": "Let the inner triangle's base be y and write the shaded (trapezium-like) area in terms of y.",
            "user_id": 2,
            "created_at": "2026-05-29 17:25:09",
            "updated_at": "2026-05-29 17:25:09"
        },
        {
            "id": 43611,
            "question_id": 29335,
            "hint_level": 2,
            "hint_text": "Solve 2y + 2 = 22, then add the 2 cm to get AD.",
            "user_id": 2,
            "created_at": "2026-05-29 17:25:09",
            "updated_at": "2026-05-29 17:25:09"
        },
        {
            "id": 43682,
            "question_id": 29371,
            "hint_level": 1,
            "hint_text": "Let Nurul's leftover be u and express both girls' starting and spent amounts in terms of u.",
            "user_id": 2,
            "created_at": "2026-05-29 17:25:15",
            "updated_at": "2026-05-29 17:25:15"
        },
        {
            "id": 43683,
            "question_id": 29371,
            "hint_level": 2,
            "hint_text": "The two starting amounts add to $60.",
            "user_id": 2,
            "created_at": "2026-05-29 17:25:15",
            "updated_at": "2026-05-29 17:25:15"
        },
        {
            "id": 43694,
            "question_id": 29377,
            "hint_level": 1,
            "hint_text": "Set the two expressions for the cupboard height equal.",
            "user_id": 2,
            "created_at": "2026-05-29 17:25:15",
            "updated_at": "2026-05-29 17:25:15"
        },
        {
            "id": 43695,
            "question_id": 29377,
            "hint_level": 2,
            "hint_text": "Use 2B = 0.9 m = 90 cm to find the box length and then the height.",
            "user_id": 2,
            "created_at": "2026-05-29 17:25:15",
            "updated_at": "2026-05-29 17:25:15"
        },
        {
            "id": 43700,
            "question_id": 29380,
            "hint_level": 1,
            "hint_text": "Let Kathy's end amount be u and Alice's be 2u; express their starting amounts.",
            "user_id": 2,
            "created_at": "2026-05-29 17:25:15",
            "updated_at": "2026-05-29 17:25:15"
        },
        {
            "id": 43701,
            "question_id": 29380,
            "hint_level": 2,
            "hint_text": "Apply the first ratio 3 : 4 to the starting amounts and solve.",
            "user_id": 2,
            "created_at": "2026-05-29 17:25:15",
            "updated_at": "2026-05-29 17:25:15"
        },
        {
            "id": 43840,
            "question_id": 29450,
            "hint_level": 1,
            "hint_text": "Set up units for Paul and Zalim's spending and 'left' amounts, then total to $140.20.",
            "user_id": 2,
            "created_at": "2026-05-29 17:25:28",
            "updated_at": "2026-05-29 17:25:28"
        },
        {
            "id": 43841,
            "question_id": 29450,
            "hint_level": 2,
            "hint_text": "Key: 37 units = $125.80, 1 unit = $3.40; Paul spent = $17, Zalim at first = $77.20.",
            "user_id": 2,
            "created_at": "2026-05-29 17:25:28",
            "updated_at": "2026-05-29 17:25:28"
        },
        {
            "id": 44002,
            "question_id": 29531,
            "hint_level": 1,
            "hint_text": "Let the girls' average be 1 unit; the boys' average is 1 unit + $1.",
            "user_id": 2,
            "created_at": "2026-05-29 17:34:47",
            "updated_at": "2026-05-29 17:34:47"
        },
        {
            "id": 44003,
            "question_id": 29531,
            "hint_level": 2,
            "hint_text": "Total boys' money = girls' total + $10; set up the equation and solve for the unit.",
            "user_id": 2,
            "created_at": "2026-05-29 17:34:47",
            "updated_at": "2026-05-29 17:34:47"
        },
        {
            "id": 44396,
            "question_id": 29728,
            "hint_level": 1,
            "hint_text": "Let Belle's present age be b; Andy is 2b now.",
            "user_id": 2,
            "created_at": "2026-05-29 17:35:47",
            "updated_at": "2026-05-29 17:35:47"
        },
        {
            "id": 44397,
            "question_id": 29728,
            "hint_level": 2,
            "hint_text": "Express their ages 2 years ago and use the difference n.",
            "user_id": 2,
            "created_at": "2026-05-29 17:35:47",
            "updated_at": "2026-05-29 17:35:47"
        },
        {
            "id": 44420,
            "question_id": 29740,
            "hint_level": 1,
            "hint_text": "Let the triangle = 4 units and rectangle = 8 units.",
            "user_id": 2,
            "created_at": "2026-05-29 17:35:48",
            "updated_at": "2026-05-29 17:35:48"
        },
        {
            "id": 44421,
            "question_id": 29740,
            "hint_level": 2,
            "hint_text": "Account for the overlap when finding the total area of the figure.",
            "user_id": 2,
            "created_at": "2026-05-29 17:35:48",
            "updated_at": "2026-05-29 17:35:48"
        },
        {
            "id": 44642,
            "question_id": 29851,
            "hint_level": 1,
            "hint_text": "Track apples and oranges separately through the exchange and give-away.",
            "user_id": 2,
            "created_at": "2026-05-29 17:36:04",
            "updated_at": "2026-05-29 17:36:04"
        },
        {
            "id": 44643,
            "question_id": 29851,
            "hint_level": 2,
            "hint_text": "For (b), pack in 4 : 5 groups and find the leftover oranges.",
            "user_id": 2,
            "created_at": "2026-05-29 17:36:04",
            "updated_at": "2026-05-29 17:36:04"
        },
        {
            "id": 44644,
            "question_id": 29852,
            "hint_level": 1,
            "hint_text": "Set up the combined-volume equation with Y's height as the unknown.",
            "user_id": 2,
            "created_at": "2026-05-29 17:36:04",
            "updated_at": "2026-05-29 17:36:04"
        },
        {
            "id": 44645,
            "question_id": 29852,
            "hint_level": 2,
            "hint_text": "For (b), find the volume poured out and divide by X's original water volume.",
            "user_id": 2,
            "created_at": "2026-05-29 17:36:04",
            "updated_at": "2026-05-29 17:36:04"
        },
        {
            "id": 44738,
            "question_id": 29899,
            "hint_level": 1,
            "hint_text": "Set up: total value before + new bags = new average x new count.",
            "user_id": 2,
            "created_at": "2026-05-29 17:36:08",
            "updated_at": "2026-05-29 17:36:08"
        },
        {
            "id": 44739,
            "question_id": 29899,
            "hint_level": 2,
            "hint_text": "350u + 1850 = 400(u + 2) gives u = 21.",
            "user_id": 2,
            "created_at": "2026-05-29 17:36:08",
            "updated_at": "2026-05-29 17:36:08"
        },
        {
            "id": 44750,
            "question_id": 29905,
            "hint_level": 1,
            "hint_text": "Use the difference 26 - 19 to find the small rectangle's width.",
            "user_id": 2,
            "created_at": "2026-05-29 17:36:09",
            "updated_at": "2026-05-29 17:36:09"
        },
        {
            "id": 44751,
            "question_id": 29905,
            "hint_level": 2,
            "hint_text": "Shaded area = big rectangle - 6 small rectangles = 494 - 325.5 = 168.5 cm².",
            "user_id": 2,
            "created_at": "2026-05-29 17:36:09",
            "updated_at": "2026-05-29 17:36:09"
        },
        {
            "id": 44822,
            "question_id": 29941,
            "hint_level": 1,
            "hint_text": "Write the total before and after adding the book.",
            "user_id": 2,
            "created_at": "2026-05-29 17:36:12",
            "updated_at": "2026-05-29 17:36:12"
        },
        {
            "id": 44823,
            "question_id": 29941,
            "hint_level": 2,
            "hint_text": "Set the new average equal to 18 and solve.",
            "user_id": 2,
            "created_at": "2026-05-29 17:36:12",
            "updated_at": "2026-05-29 17:36:12"
        },
        {
            "id": 44864,
            "question_id": 29962,
            "hint_level": 1,
            "hint_text": "Discounted price is 75% of the original.",
            "user_id": 2,
            "created_at": "2026-05-29 17:36:13",
            "updated_at": "2026-05-29 17:36:13"
        },
        {
            "id": 44865,
            "question_id": 29962,
            "hint_level": 2,
            "hint_text": "Set up: (discounted units x 0.75p) + (full-price units x p) = 32 330.",
            "user_id": 2,
            "created_at": "2026-05-29 17:36:13",
            "updated_at": "2026-05-29 17:36:13"
        },
        {
            "id": 44884,
            "question_id": 29972,
            "hint_level": 1,
            "hint_text": "Let Betty = 3 units so Ann = 1 unit.",
            "user_id": 2,
            "created_at": "2026-05-29 17:36:14",
            "updated_at": "2026-05-29 17:36:14"
        },
        {
            "id": 44885,
            "question_id": 29972,
            "hint_level": 2,
            "hint_text": "Charles = 5\/6 of (Ann + Betty); scale to whole numbers.",
            "user_id": 2,
            "created_at": "2026-05-29 17:36:14",
            "updated_at": "2026-05-29 17:36:14"
        },
        {
            "id": 45202,
            "question_id": 30131,
            "hint_level": 1,
            "hint_text": "Set up the average equation before and after the two new toys.",
            "user_id": 2,
            "created_at": "2026-05-29 18:06:00",
            "updated_at": "2026-05-29 18:06:00"
        },
        {
            "id": 45203,
            "question_id": 30131,
            "hint_level": 2,
            "hint_text": "Total cost = final average x total number of toys.",
            "user_id": 2,
            "created_at": "2026-05-29 18:06:00",
            "updated_at": "2026-05-29 18:06:00"
        },
        {
            "id": 45854,
            "question_id": 30457,
            "hint_level": 1,
            "hint_text": "The total number of cards stays the same: 18n = 12(n + 4).",
            "user_id": 2,
            "created_at": "2026-05-29 18:06:33",
            "updated_at": "2026-05-29 18:06:33"
        },
        {
            "id": 45855,
            "question_id": 30457,
            "hint_level": 2,
            "hint_text": "Solve for n = 8; total = 8 x 18 = 144.",
            "user_id": 2,
            "created_at": "2026-05-29 18:06:33",
            "updated_at": "2026-05-29 18:06:33"
        },
        {
            "id": 46048,
            "question_id": 30554,
            "hint_level": 1,
            "hint_text": "Pick a total that makes \\(\\dfrac{1}{4}\\) and \\(\\dfrac{4}{9}\\) whole (e.g. 36u).",
            "user_id": 2,
            "created_at": "2026-05-29 18:06:43",
            "updated_at": "2026-05-29 18:06:43"
        },
        {
            "id": 46049,
            "question_id": 30554,
            "hint_level": 2,
            "hint_text": "Total photocards = 5 × adults + 4 × boys + 3 × girls = 1932.",
            "user_id": 2,
            "created_at": "2026-05-29 18:06:43",
            "updated_at": "2026-05-29 18:06:43"
        },
        {
            "id": 46312,
            "question_id": 30686,
            "hint_level": 1,
            "hint_text": "Let the parts left be 5u (red) and 9u (blue); the 9u is 75% of the original blue.",
            "user_id": 2,
            "created_at": "2026-05-29 18:07:08",
            "updated_at": "2026-05-29 18:07:08"
        },
        {
            "id": 46313,
            "question_id": 30686,
            "hint_level": 2,
            "hint_text": "Form an equation for the total of 329 to find u.",
            "user_id": 2,
            "created_at": "2026-05-29 18:07:08",
            "updated_at": "2026-05-29 18:07:08"
        },
        {
            "id": 46470,
            "question_id": 30765,
            "hint_level": 1,
            "hint_text": "Let Ahmad = 4 units so Caili = 5 units; Banu = 4 × Ahmad = 16 units.",
            "user_id": 2,
            "created_at": "2026-05-29 18:07:22",
            "updated_at": "2026-05-29 18:07:22"
        },
        {
            "id": 46471,
            "question_id": 30765,
            "hint_level": 2,
            "hint_text": "Total = 25 units = 725, so 1 unit = 29; Banu = 16 × 29.",
            "user_id": 2,
            "created_at": "2026-05-29 18:07:22",
            "updated_at": "2026-05-29 18:07:22"
        },
        {
            "id": 46528,
            "question_id": 30795,
            "hint_level": 1,
            "hint_text": "Let the number of each flavour be n.",
            "user_id": 2,
            "created_at": "2026-05-29 18:07:23",
            "updated_at": "2026-05-29 18:07:23"
        },
        {
            "id": 46529,
            "question_id": 30795,
            "hint_level": 2,
            "hint_text": "Set Jane's leftovers in the ratio 1 : 4 and solve.",
            "user_id": 2,
            "created_at": "2026-05-29 18:07:23",
            "updated_at": "2026-05-29 18:07:23"
        },
        {
            "id": 46554,
            "question_id": 30808,
            "hint_level": 1,
            "hint_text": "Paul's pens do not change, so keep his units constant.",
            "user_id": 2,
            "created_at": "2026-05-29 18:07:23",
            "updated_at": "2026-05-29 18:07:23"
        },
        {
            "id": 46555,
            "question_id": 30808,
            "hint_level": 2,
            "hint_text": "Set the new ratio 2 : 1 and solve for u.",
            "user_id": 2,
            "created_at": "2026-05-29 18:07:23",
            "updated_at": "2026-05-29 18:07:23"
        },
        {
            "id": 46562,
            "question_id": 30812,
            "hint_level": 1,
            "hint_text": "Express both amounts in terms of David's money x.",
            "user_id": 2,
            "created_at": "2026-05-29 18:07:24",
            "updated_at": "2026-05-29 18:07:24"
        },
        {
            "id": 46563,
            "question_id": 30812,
            "hint_level": 2,
            "hint_text": "After the $21 transfer, set Adam = 4 × David.",
            "user_id": 2,
            "created_at": "2026-05-29 18:07:24",
            "updated_at": "2026-05-29 18:07:24"
        },
        {
            "id": 46622,
            "question_id": 30842,
            "hint_level": 1,
            "hint_text": "Let the orchids left be a unit; express lilies and tulips left in terms of it.",
            "user_id": 2,
            "created_at": "2026-05-29 18:07:25",
            "updated_at": "2026-05-29 18:07:25"
        },
        {
            "id": 46623,
            "question_id": 30842,
            "hint_level": 2,
            "hint_text": "Use the total of 64 left, then add the 20 lilies sold.",
            "user_id": 2,
            "created_at": "2026-05-29 18:07:25",
            "updated_at": "2026-05-29 18:07:25"
        },
        {
            "id": 46684,
            "question_id": 30873,
            "hint_level": 1,
            "hint_text": "Set up muffins per packet as u and tarts per box as u + 9.",
            "user_id": 2,
            "created_at": "2026-05-29 18:07:26",
            "updated_at": "2026-05-29 18:07:26"
        },
        {
            "id": 46685,
            "question_id": 30873,
            "hint_level": 2,
            "hint_text": "Use muffins : tarts = 68 : 32 to form an equation and solve for u.",
            "user_id": 2,
            "created_at": "2026-05-29 18:07:26",
            "updated_at": "2026-05-29 18:07:26"
        },
        {
            "id": 46842,
            "question_id": 30952,
            "hint_level": 1,
            "hint_text": "After the first transfer, let Kate be 1 unit and Dan 3 units.",
            "user_id": 2,
            "created_at": "2026-05-29 18:07:30",
            "updated_at": "2026-05-29 18:07:30"
        },
        {
            "id": 46843,
            "question_id": 30952,
            "hint_level": 2,
            "hint_text": "Set up the second condition (Dan = twice Kate) and solve for the unit.",
            "user_id": 2,
            "created_at": "2026-05-29 18:07:30",
            "updated_at": "2026-05-29 18:07:30"
        },
        {
            "id": 46850,
            "question_id": 30956,
            "hint_level": 1,
            "hint_text": "She used 180 ÷ 10 = 18 ten-dollar notes paying for the suitcase.",
            "user_id": 2,
            "created_at": "2026-05-29 18:07:30",
            "updated_at": "2026-05-29 18:07:30"
        },
        {
            "id": 46851,
            "question_id": 30956,
            "hint_level": 2,
            "hint_text": "Set up two-dollar notes = 4 × ten-dollar notes left, using the 12-more relationship.",
            "user_id": 2,
            "created_at": "2026-05-29 18:07:30",
            "updated_at": "2026-05-29 18:07:30"
        },
        {
            "id": 47040,
            "question_id": 31051,
            "hint_level": 1,
            "hint_text": "Express bag, wallet and dress in terms of her total money u.",
            "user_id": 2,
            "created_at": "2026-05-29 18:07:39",
            "updated_at": "2026-05-29 18:07:39"
        },
        {
            "id": 47041,
            "question_id": 31051,
            "hint_level": 2,
            "hint_text": "The dress cost = remaining money; set up and solve, then compute the wallet.",
            "user_id": 2,
            "created_at": "2026-05-29 18:07:39",
            "updated_at": "2026-05-29 18:07:39"
        },
        {
            "id": 47250,
            "question_id": 31156,
            "hint_level": 1,
            "hint_text": "Sister = s, Matthew = 3s now; add 5 to each for their future ages.",
            "user_id": 2,
            "created_at": "2026-05-29 18:07:46",
            "updated_at": "2026-05-29 18:07:46"
        },
        {
            "id": 47251,
            "question_id": 31156,
            "hint_level": 2,
            "hint_text": "Set the future total equal to h and solve for s.",
            "user_id": 2,
            "created_at": "2026-05-29 18:07:46",
            "updated_at": "2026-05-29 18:07:46"
        },
        {
            "id": 47294,
            "question_id": 31178,
            "hint_level": 1,
            "hint_text": "Let C = 1 unit, then express A and B in the same units.",
            "user_id": 2,
            "created_at": "2026-05-29 18:07:47",
            "updated_at": "2026-05-29 18:07:47"
        },
        {
            "id": 47295,
            "question_id": 31178,
            "hint_level": 2,
            "hint_text": "Fraction = A units ÷ total units.",
            "user_id": 2,
            "created_at": "2026-05-29 18:07:47",
            "updated_at": "2026-05-29 18:07:47"
        }
    ]
}