{
  "paper": {
    "school": "St Hilda",
    "year": 2024,
    "level": "P4",
    "label": "Term 3 Review",
    "source_prefix": "St Hilda 2024 P4 Term 3 Review",
    "has_answer_key": true
  },
  "questions": [
    {
      "n": 1,
      "type_id": 1,
      "question": "The table shows the number of curry puffs Mr Ali sold on Sunday. How many potato curry puffs were sold on Sunday?",
      "answer0": "138",
      "answer1": "178",
      "answer2": "188",
      "answer3": "402",
      "correct_answer": 1,
      "skill_id": 148,
      "difficulty_id": 1,
      "explanation": "Total = 290, chicken = 112. Potato = 290 − 112 = 178.",
      "hints": ["Total = chicken + potato.", "Subtract the chicken curry puffs from the total."],
      "source": "St Hilda 2024 P4 Term 3 Review Q1",
      "image_needed": true,
      "image_options": false,
      "image_file": "q1.png",
      "image_page": 1,
      "image_bbox": [0.18, 0.55, 0.88, 0.66],
      "image_loc": "table in the middle of the page below the question",
      "notes": ""
    },
    {
      "n": 2,
      "type_id": 1,
      "question": "Name the angle.",
      "answer0": "∠ABC",
      "answer1": "∠AXB",
      "answer2": "∠BXC",
      "answer3": "∠XBC",
      "correct_answer": 0,
      "skill_id": 139,
      "difficulty_id": 1,
      "explanation": "The angle is formed at vertex B by rays BA and BC, so it is named ∠ABC (or ∠CBA). The middle letter is the vertex.",
      "hints": ["The vertex of the angle is the middle letter.", "The vertex is the point where the two rays meet, B."],
      "source": "St Hilda 2024 P4 Term 3 Review Q2",
      "image_needed": true,
      "image_options": false,
      "image_file": "q2.png",
      "image_page": 2,
      "image_bbox": [0.25, 0.13, 0.72, 0.27],
      "image_loc": "angle diagram with rays A, B, C below the question",
      "notes": ""
    },
    {
      "n": 3,
      "type_id": 1,
      "question": "In the figure, how many angles are smaller than a right angle?",
      "answer0": "1",
      "answer1": "2",
      "answer2": "3",
      "answer3": "4",
      "correct_answer": 1,
      "skill_id": 99,
      "difficulty_id": 2,
      "explanation": "The figure is a trapezium with two acute angles (the bottom-left and bottom-right base angles are smaller than a right angle) and two obtuse angles at the top. So 2 angles are smaller than a right angle.",
      "hints": ["An angle smaller than a right angle is acute (less than 90°).", "Compare each corner to a right angle (a square corner)."],
      "source": "St Hilda 2024 P4 Term 3 Review Q3",
      "image_needed": true,
      "image_options": false,
      "image_file": "q3.png",
      "image_page": 2,
      "image_bbox": [0.28, 0.50, 0.66, 0.64],
      "image_loc": "trapezium figure with marked angles in the middle of the page",
      "notes": "Answer key: 2 (option 2)."
    },
    {
      "n": 4,
      "type_id": 1,
      "question": "Express \\(2\\dfrac{3}{5}\\) as an improper fraction.",
      "answer0": "\\(\\dfrac{6}{5}\\)",
      "answer1": "\\(\\dfrac{13}{5}\\)",
      "answer2": "\\(\\dfrac{17}{5}\\)",
      "answer3": "\\(\\dfrac{23}{5}\\)",
      "correct_answer": 1,
      "skill_id": 119,
      "difficulty_id": 1,
      "explanation": "\\(2\\dfrac{3}{5} = \\dfrac{2\\times 5 + 3}{5} = \\dfrac{13}{5}\\).",
      "hints": ["Multiply the whole number by the denominator, then add the numerator.", "Keep the same denominator."],
      "source": "St Hilda 2024 P4 Term 3 Review Q4",
      "image_needed": false,
      "image_options": false,
      "image_file": null,
      "notes": ""
    },
    {
      "n": 5,
      "type_id": 1,
      "question": "What is \\(\\dfrac{5}{8}\\) of 24?",
      "answer0": "15",
      "answer1": "29",
      "answer2": "100",
      "answer3": "192",
      "correct_answer": 0,
      "skill_id": 120,
      "difficulty_id": 1,
      "explanation": "\\(\\dfrac{5}{8} \\times 24 = \\dfrac{5 \\times 24}{8} = \\dfrac{120}{8} = 15\\).",
      "hints": ["Divide 24 by the denominator 8 to find one part.", "Multiply that part by the numerator 5."],
      "source": "St Hilda 2024 P4 Term 3 Review Q5",
      "image_needed": false,
      "image_options": false,
      "image_file": null,
      "notes": ""
    },
    {
      "n": 6,
      "type_id": 1,
      "question": "Find the sum of \\(\\dfrac{1}{3}\\) and \\(\\dfrac{1}{2}\\).",
      "answer0": "\\(\\dfrac{2}{5}\\)",
      "answer1": "\\(\\dfrac{1}{6}\\)",
      "answer2": "\\(\\dfrac{2}{6}\\)",
      "answer3": "\\(\\dfrac{5}{6}\\)",
      "correct_answer": 3,
      "skill_id": 121,
      "difficulty_id": 1,
      "explanation": "\\(\\dfrac{1}{3} + \\dfrac{1}{2} = \\dfrac{2}{6} + \\dfrac{3}{6} = \\dfrac{5}{6}\\).",
      "hints": ["Find a common denominator (6).", "Convert both fractions then add the numerators."],
      "source": "St Hilda 2024 P4 Term 3 Review Q6",
      "image_needed": false,
      "image_options": false,
      "image_file": null,
      "notes": ""
    },
    {
      "n": 7,
      "type_id": 1,
      "question": "The line graph shows the number of members in a Reading Club from January to April. The greatest decrease in the number of members is from ____________ to ____________.",
      "answer0": "January to February",
      "answer1": "January to April",
      "answer2": "February to March",
      "answer3": "March to April",
      "correct_answer": 3,
      "skill_id": 147,
      "difficulty_id": 2,
      "explanation": "Jan=25, Feb=15, Mar=30, Apr=10. Decreases: Jan→Feb = 10; Mar→Apr = 20. The greatest decrease is from March to April (20 members).",
      "hints": ["A decrease is where the line goes down.", "Find the steepest downward segment and compute the drop."],
      "source": "St Hilda 2024 P4 Term 3 Review Q7",
      "image_needed": true,
      "image_options": false,
      "image_file": "q7.png",
      "image_page": 4,
      "image_bbox": [0.17, 0.13, 0.92, 0.46],
      "image_loc": "Reading Club Membership line graph below the question",
      "notes": ""
    },
    {
      "n": 8,
      "type_id": 1,
      "question": "Subtract \\(\\dfrac{7}{9}\\) from 5.",
      "answer0": "\\(\\dfrac{2}{9}\\)",
      "answer1": "\\(\\dfrac{35}{9}\\)",
      "answer2": "\\(4\\dfrac{2}{9}\\)",
      "answer3": "\\(5\\dfrac{7}{9}\\)",
      "correct_answer": 2,
      "skill_id": 121,
      "difficulty_id": 2,
      "explanation": "\\(5 - \\dfrac{7}{9} = 4\\dfrac{9}{9} - \\dfrac{7}{9} = 4\\dfrac{2}{9}\\).",
      "hints": ["Rename 5 as \\(4\\dfrac{9}{9}\\) to subtract the ninths.", "Subtract the fractions, keep the whole number part."],
      "source": "St Hilda 2024 P4 Term 3 Review Q8",
      "image_needed": false,
      "image_options": false,
      "image_file": null,
      "notes": ""
    },
    {
      "n": 9,
      "type_id": 1,
      "question": "A ribbon is \\(\\dfrac{1}{4}\\) m long. A string is \\(\\dfrac{1}{6}\\) m longer than the ribbon. What is the total length of the ribbon and string?",
      "answer0": "\\(\\dfrac{1}{6}\\) m",
      "answer1": "\\(\\dfrac{5}{12}\\) m",
      "answer2": "\\(\\dfrac{7}{12}\\) m",
      "answer3": "\\(\\dfrac{2}{3}\\) m",
      "correct_answer": 3,
      "skill_id": 122,
      "difficulty_id": 2,
      "explanation": "String = \\(\\dfrac{1}{4} + \\dfrac{1}{6} = \\dfrac{3}{12} + \\dfrac{2}{12} = \\dfrac{5}{12}\\) m. Total = ribbon + string = \\(\\dfrac{1}{4} + \\dfrac{5}{12} = \\dfrac{3}{12} + \\dfrac{5}{12} = \\dfrac{8}{12} = \\dfrac{2}{3}\\) m.",
      "hints": ["First find the string's length: ribbon + \\(\\dfrac{1}{6}\\).", "Then add the ribbon and string lengths together."],
      "source": "St Hilda 2024 P4 Term 3 Review Q9",
      "image_needed": false,
      "image_options": false,
      "image_file": null,
      "notes": ""
    },
    {
      "n": 10,
      "type_id": 1,
      "question": "Which of the following statements is true?",
      "answer0": "∠AOB is an obtuse angle.",
      "answer1": "∠AOC is an acute angle.",
      "answer2": "∠BOC is a right angle.",
      "answer3": "∠COD is an acute angle.",
      "correct_answer": 3,
      "skill_id": 99,
      "difficulty_id": 2,
      "explanation": "On line AD with rays OB and OC above it: ∠AOB is acute, ∠AOC is obtuse, ∠BOC is acute, and ∠COD is acute (less than 90°). So statement (4) is true.",
      "hints": ["Acute < 90°, right = 90°, obtuse > 90°.", "Check each named angle against the line AD."],
      "source": "St Hilda 2024 P4 Term 3 Review Q10",
      "image_needed": true,
      "image_options": false,
      "image_file": "q10.png",
      "image_page": 6,
      "image_bbox": [0.22, 0.13, 0.74, 0.27],
      "image_loc": "angle diagram with line AOD and rays OB, OC below the question",
      "notes": ""
    },
    {
      "n": 11,
      "type_id": 1,
      "question": "There were 72 marbles in a box. \\(\\dfrac{1}{8}\\) of the marbles are blue. The rest are red. How many more red marbles than blue marbles are there?",
      "answer0": "9",
      "answer1": "54",
      "answer2": "63",
      "answer3": "80",
      "correct_answer": 1,
      "skill_id": 120,
      "difficulty_id": 2,
      "explanation": "Blue = \\(\\dfrac{1}{8} \\times 72 = 9\\). Red = 72 − 9 = 63. Difference = 63 − 9 = 54.",
      "hints": ["Find the number of blue marbles first.", "Red = total − blue, then subtract blue from red."],
      "source": "St Hilda 2024 P4 Term 3 Review Q11",
      "image_needed": false,
      "image_options": false,
      "image_file": null,
      "notes": ""
    },
    {
      "n": 12,
      "type_id": 1,
      "question": "The table shows the number of stickers five friends collected. Who collected the least number of stickers?",
      "answer0": "Rita",
      "answer1": "Tina",
      "answer2": "Uma",
      "answer3": "Violet",
      "correct_answer": 2,
      "skill_id": 147,
      "difficulty_id": 1,
      "explanation": "Rita=76, Sam=152, Tina=123, Uma=52, Violet=304. The smallest value is 52, so Uma collected the least.",
      "hints": ["Look for the smallest number in the table.", "Compare all five totals."],
      "source": "St Hilda 2024 P4 Term 3 Review Q12",
      "image_needed": true,
      "image_options": false,
      "image_file": "q12.png",
      "image_page": 7,
      "image_bbox": [0.31, 0.13, 0.69, 0.30],
      "image_loc": "sticker totals table near the top of the page",
      "notes": "Shared figure for Q12 and Q13."
    },
    {
      "n": 13,
      "type_id": 1,
      "question": "Who collected twice as many stickers as Sam?",
      "answer0": "Rita",
      "answer1": "Tina",
      "answer2": "Uma",
      "answer3": "Violet",
      "correct_answer": 3,
      "skill_id": 148,
      "difficulty_id": 1,
      "explanation": "Sam = 152. Twice 152 = 304, which is Violet's total. So Violet collected twice as many as Sam.",
      "hints": ["Twice means multiply Sam's total by 2.", "Find whose total equals 2 × 152."],
      "source": "St Hilda 2024 P4 Term 3 Review Q13",
      "image_needed": true,
      "image_options": false,
      "image_file": "q12.png",
      "image_page": 7,
      "image_bbox": [0.31, 0.13, 0.69, 0.30],
      "image_loc": "same sticker totals table as Q12 near the top of page 7",
      "notes": "Uses the same table as Q12."
    },
    {
      "n": 14,
      "type_id": 1,
      "question": "What is the improper fraction represented by the letter A on the number line?",
      "answer0": "\\(\\dfrac{22}{5}\\)",
      "answer1": "\\(\\dfrac{23}{5}\\)",
      "answer2": "\\(\\dfrac{24}{5}\\)",
      "answer3": "\\(\\dfrac{18}{5}\\)",
      "correct_answer": 1,
      "skill_id": 119,
      "difficulty_id": 2,
      "explanation": "Each interval between 4 and 5 is \\(\\dfrac{1}{5}\\). A is at the 3rd mark after 4, i.e. \\(4\\dfrac{3}{5} = \\dfrac{23}{5}\\).",
      "hints": ["Count the equal parts between two whole numbers.", "A is three fifths past 4, so \\(4\\dfrac{3}{5}\\) as an improper fraction."],
      "source": "St Hilda 2024 P4 Term 3 Review Q14",
      "image_needed": true,
      "image_options": false,
      "image_file": "q14.png",
      "image_page": 8,
      "image_bbox": [0.12, 0.20, 0.92, 0.30],
      "image_loc": "number line from 4 to 6 with arrow A and 25/5 marked",
      "notes": "Answer key: 23/5. Made MCQ because answer is a fraction (FIB must be integer/decimal only)."
    },
    {
      "n": 15,
      "type_id": 1,
      "question": "What fraction of the set is shaded? Give your answer as a fraction in the simplest form.",
      "answer0": "\\(\\dfrac{6}{9}\\)",
      "answer1": "\\(\\dfrac{2}{3}\\)",
      "answer2": "\\(\\dfrac{3}{9}\\)",
      "answer3": "\\(\\dfrac{1}{3}\\)",
      "correct_answer": 1,
      "skill_id": 120,
      "difficulty_id": 2,
      "explanation": "There are 9 diamonds in total; 6 are shaded. \\(\\dfrac{6}{9} = \\dfrac{2}{3}\\) in simplest form.",
      "hints": ["Count shaded shapes over total shapes.", "Simplify the fraction by dividing top and bottom by 3."],
      "source": "St Hilda 2024 P4 Term 3 Review Q15",
      "image_needed": true,
      "image_options": false,
      "image_file": "q15.png",
      "image_page": 8,
      "image_bbox": [0.19, 0.47, 0.88, 0.57],
      "image_loc": "row of 9 diamonds (6 shaded, 3 unshaded) grouped in three boxes",
      "notes": "Answer key: 6/9 = 2/3. Made MCQ because answer is a fraction (FIB must be integer/decimal only)."
    },
    {
      "n": 16,
      "type_id": 2,
      "question": "The table shows the number of students who are right-handed and left-handed in Classes 4A and 4B. Fill in the missing numbers. Total of 4A = [?]. Right-handed in 4B = [?].",
      "answer0": "40",
      "answer1": "29",
      "answer2": null,
      "answer3": null,
      "correct_answer": null,
      "skill_id": 146,
      "difficulty_id": 2,
      "explanation": "(a) Total of 4A = right-handed + left-handed = 33 + 7 = 40. (b) Right-handed in 4B = total − left-handed = 38 − 9 = 29.",
      "hints": ["Each column total = right-handed + left-handed.", "(a) add 4A's two values; (b) subtract 4B's left-handed from its total."],
      "source": "St Hilda 2024 P4 Term 3 Review Q16",
      "image_needed": true,
      "image_options": false,
      "image_file": "q16.png",
      "image_page": 9,
      "image_bbox": [0.20, 0.18, 0.90, 0.46],
      "image_loc": "two-way table of right/left-handed students for 4A and 4B",
      "notes": "Two blanks: (a) total 4A = 40, (b) right-handed 4B = 29. answer0=40 (blank a), answer1=29 (blank b)."
    },
    {
      "n": 17,
      "type_id": 2,
      "question": "The line graph shows the mass of apples sold in a fruit shop. What was the total mass of apples sold from Monday to Wednesday? [?]",
      "answer0": "90",
      "answer1": null,
      "answer2": null,
      "answer3": null,
      "correct_answer": null,
      "skill_id": 147,
      "difficulty_id": 2,
      "explanation": "Monday = 20 kg, Tuesday = 20 kg, Wednesday = 50 kg. Total = 20 + 20 + 50 = 90 kg.",
      "hints": ["Read the mass for each of the three days from the graph.", "Add the three masses together."],
      "source": "St Hilda 2024 P4 Term 3 Review Q17",
      "image_needed": true,
      "image_options": false,
      "image_file": "q17.png",
      "image_page": 10,
      "image_bbox": [0.13, 0.13, 0.90, 0.46],
      "image_loc": "Mass of apples sold in a week line graph below the question",
      "notes": "Answer in kg. Key: 20+20+50 = 90 kg."
    },
    {
      "n": 18,
      "type_id": 1,
      "question": "Name the smallest angle in the figure.",
      "answer0": "∠a",
      "answer1": "∠b",
      "answer2": "∠c",
      "answer3": "∠d",
      "correct_answer": 3,
      "skill_id": 140,
      "difficulty_id": 2,
      "explanation": "In the kite-shaped figure, angle d (at the bottom vertex) is the most pointed/narrowest, so ∠d is the smallest angle.",
      "hints": ["The smallest angle is the most 'closed' or pointed corner.", "Compare the openings of angles a, b, c and d."],
      "source": "St Hilda 2024 P4 Term 3 Review Q18",
      "image_needed": true,
      "image_options": false,
      "image_file": "q18.png",
      "image_page": 10,
      "image_bbox": [0.33, 0.66, 0.56, 0.82],
      "image_loc": "kite/rhombus figure with angles a, b, c, d marked",
      "notes": "Answer key: ∠d. Converted to MCQ with the four labelled angles as options."
    },
    {
      "n": 19,
      "type_id": 2,
      "question": "Measure and write down the size of angle x. [?]",
      "answer0": "32",
      "answer1": null,
      "answer2": null,
      "answer3": null,
      "correct_answer": null,
      "skill_id": 140,
      "difficulty_id": 2,
      "explanation": "Measuring angle x with a protractor gives 32°.",
      "hints": ["Place the protractor's centre on the vertex of angle x.", "Read the scale where the second ray crosses."],
      "source": "St Hilda 2024 P4 Term 3 Review Q19",
      "image_needed": true,
      "image_options": false,
      "image_file": "q19.png",
      "image_page": 11,
      "image_bbox": [0.36, 0.15, 0.68, 0.28],
      "image_loc": "acute angle x diagram below the question",
      "notes": "Answer in degrees (°). Key: 32°."
    },
    {
      "n": 20,
      "type_id": 0,
      "question": "Draw ∠ABC = 162° using the given line AB. Mark and label the angle.",
      "answer0": null,
      "answer1": null,
      "answer2": null,
      "answer3": null,
      "correct_answer": null,
      "skill_id": 140,
      "difficulty_id": 2,
      "explanation": "Using the protractor on line AB, measure 162° from BA at vertex B and draw ray BC; label ∠ABC = 162°.",
      "hints": [],
      "source": "St Hilda 2024 P4 Term 3 Review Q20",
      "image_needed": true,
      "image_options": false,
      "image_file": "q20.png",
      "image_page": 11,
      "image_bbox": [0.30, 0.46, 0.82, 0.74],
      "image_loc": "protractor on line AB with vertex B",
      "notes": "Interactive draw/construct task — no app question type. type_id 0, skipped on insert. Answer: construct a 162° angle."
    },
    {
      "n": 21,
      "type_id": 2,
      "question": "The table shows the different types of canned drinks sold. A total of 500 canned drinks were sold in a week. How many cans of Milo were sold? [?]",
      "answer0": "125",
      "answer1": null,
      "answer2": null,
      "answer3": null,
      "correct_answer": null,
      "skill_id": 118,
      "difficulty_id": 2,
      "explanation": "Water + Orange Juice = 252 + 123 = 375. Milo = 500 − 375 = 125.",
      "hints": ["Add the two known amounts first.", "Subtract that sum from the total of 500."],
      "source": "St Hilda 2024 P4 Term 3 Review Q21",
      "image_needed": true,
      "image_options": false,
      "image_file": "q21.png",
      "image_page": 12,
      "image_bbox": [0.27, 0.18, 0.73, 0.33],
      "image_loc": "canned drinks table below the question",
      "notes": "Key: 252+123=375; 500−375 = 125."
    },
    {
      "n": 22,
      "type_id": 1,
      "question": "Container A contains \\(\\dfrac{2}{3}\\) ℓ of water. Container B contains \\(\\dfrac{1}{6}\\) ℓ lesser than Container A. What is the total capacity of Containers A and B? Express your answer as a mixed number in the simplest form.",
      "answer0": "\\(1\\dfrac{1}{6}\\) ℓ",
      "answer1": "\\(1\\dfrac{1}{3}\\) ℓ",
      "answer2": "\\(\\dfrac{5}{6}\\) ℓ",
      "answer3": "\\(1\\dfrac{1}{2}\\) ℓ",
      "correct_answer": 0,
      "skill_id": 122,
      "difficulty_id": 3,
      "explanation": "Container B = \\(\\dfrac{2}{3} - \\dfrac{1}{6} = \\dfrac{4}{6} - \\dfrac{1}{6} = \\dfrac{3}{6} = \\dfrac{1}{2}\\) ℓ. Total = \\(\\dfrac{2}{3} + \\dfrac{1}{2} = \\dfrac{4}{6} + \\dfrac{3}{6} = \\dfrac{7}{6} = 1\\dfrac{1}{6}\\) ℓ.",
      "hints": ["First find Container B's amount: A minus \\(\\dfrac{1}{6}\\).", "Add A and B, then write the answer as a mixed number."],
      "source": "St Hilda 2024 P4 Term 3 Review Q22",
      "image_needed": false,
      "image_options": false,
      "image_file": null,
      "notes": "Answer key: total = 1 1/6 ℓ. Made MCQ because answer is a mixed number (FIB must be integer/decimal only)."
    },
    {
      "n": 23,
      "type_id": 2,
      "question": "Look at the shapes. How many quarter circles are there? [?]",
      "answer0": "5",
      "answer1": null,
      "answer2": null,
      "answer3": null,
      "correct_answer": null,
      "skill_id": 221,
      "difficulty_id": 2,
      "explanation": "Three full circles make 4 quarter circles each — but counting the quarter-circle pieces: the figure has 3 whole circles plus a shape made of a quarter circle removed. The answer key gives 5 quarter circles.",
      "hints": ["A quarter circle is one-fourth of a whole circle.", "Count how many quarter-circle shapes you can identify in the figures."],
      "source": "St Hilda 2024 P4 Term 3 Review Q23",
      "image_needed": true,
      "image_options": false,
      "image_file": "q23.png",
      "image_page": 12,
      "image_bbox": [0.22, 0.72, 0.80, 0.86],
      "image_loc": "three full circles and one shape with a quarter removed",
      "notes": "Answer key: 5. Counting/identify question — crop must show all four shapes; final count = 5."
    },
    {
      "n": 24,
      "type_id": 1,
      "question": "Tessa used \\(\\dfrac{1}{4}\\) m of string to make ribbons. Marie used \\(\\dfrac{1}{3}\\) m of string more than Tessa to make ribbons. What is the total length of string used to make ribbons? Give your answer as a fraction in the simplest form.",
      "answer0": "\\(\\dfrac{5}{6}\\) m",
      "answer1": "\\(\\dfrac{7}{12}\\) m",
      "answer2": "\\(\\dfrac{2}{3}\\) m",
      "answer3": "\\(\\dfrac{11}{12}\\) m",
      "correct_answer": 0,
      "skill_id": 122,
      "difficulty_id": 3,
      "explanation": "Marie = \\(\\dfrac{1}{4} + \\dfrac{1}{3} = \\dfrac{3}{12} + \\dfrac{4}{12} = \\dfrac{7}{12}\\) m. Total = Tessa + Marie = \\(\\dfrac{1}{4} + \\dfrac{7}{12} = \\dfrac{3}{12} + \\dfrac{7}{12} = \\dfrac{10}{12} = \\dfrac{5}{6}\\) m.",
      "hints": ["Find Marie's length first: Tessa + \\(\\dfrac{1}{3}\\).", "Add Tessa's and Marie's lengths, then simplify."],
      "source": "St Hilda 2024 P4 Term 3 Review Q24",
      "image_needed": false,
      "image_options": false,
      "image_file": null,
      "notes": "Answer key: total = 5/6 m. Made MCQ because answer is a fraction (FIB must be integer/decimal only)."
    },
    {
      "n": 25,
      "type_id": 2,
      "question": "There were some marbles in a bag. John took \\(\\dfrac{2}{5}\\) of the marbles and Tim took the rest. Tim took 30 more marbles than John. How many marbles were there in the bag at first? [?]",
      "answer0": "150",
      "answer1": null,
      "answer2": null,
      "answer3": null,
      "correct_answer": null,
      "skill_id": 122,
      "difficulty_id": 3,
      "explanation": "John = \\(\\dfrac{2}{5}\\), Tim = \\(\\dfrac{3}{5}\\). Difference = \\(\\dfrac{3}{5} - \\dfrac{2}{5} = \\dfrac{1}{5}\\) = 30 marbles. So 1 unit = 30, and the whole (5 units) = 5 × 30 = 150 marbles.",
      "hints": ["John took 2 units, Tim took 3 units (5 units total).", "The difference of 1 unit equals 30; multiply to find 5 units."],
      "source": "St Hilda 2024 P4 Term 3 Review Q25",
      "image_needed": false,
      "image_options": false,
      "image_file": null,
      "notes": "Key: 150 marbles."
    },
    {
      "n": 26,
      "type_id": 2,
      "question": "The graph shows the cost of potatoes of different masses.<br>(a) Mrs Tan bought 6 kg of potatoes. She paid the cashier $50. How much change did she receive? $[?]<br>(b) Mr Lim bought 8 kg of potatoes. Mr Song bought 10 kg of potatoes. How much more money did Mr Song spend than Mr Lim? $[?]",
      "answer0": "38",
      "answer1": "4",
      "answer2": null,
      "answer3": null,
      "correct_answer": null,
      "skill_id": 148,
      "difficulty_id": 2,
      "explanation": "(a) 6 kg costs $12 (from the graph). Change = $50 − $12 = $38. (b) 8 kg costs $16, 10 kg costs $20. Mr Song spent $20 − $16 = $4 more than Mr Lim.",
      "hints": ["Read the cost for each mass off the graph.", "(a) change = $50 − cost; (b) subtract the two costs."],
      "source": "St Hilda 2024 P4 Term 3 Review Q26",
      "image_needed": true,
      "image_options": false,
      "image_file": "q26.png",
      "image_page": 15,
      "image_bbox": [0.22, 0.13, 0.74, 0.38],
      "image_loc": "cost vs mass of potatoes straight-line graph below the question",
      "notes": "Two blanks (both money, $): (a) $38, (b) $4. answer0=38 (part a), answer1=4 (part b)."
    }
  ]
}