{
  "paper": {
    "school": "Henry Park",
    "year": 2022,
    "level": "P4",
    "label": "Semestral Assessment 2",
    "source_prefix": "Henry Park 2022 P4 Semestral Assessment 2",
    "has_answer_key": true
  },
  "questions": [
    {
      "n": 1,
      "type_id": 1,
      "question": "In the number 67 540, which digit is in the tens place?",
      "answer0": "7",
      "answer1": "6",
      "answer2": "5",
      "answer3": "4",
      "correct_answer": 3,
      "skill_id": 105,
      "difficulty_id": 1,
      "explanation": "In 67 540, reading place values from the right: 0 = ones, 4 = tens, 5 = hundreds, 7 = thousands, 6 = ten thousands. The digit in the tens place is 4. Answer: 4 (option 4).",
      "hints": ["Count places from the right: ones, tens, hundreds...", "The tens digit is the second digit from the right."],
      "source": "Henry Park 2022 P4 Semestral Assessment 2 Q1",
      "image_needed": false,
      "image_options": false,
      "image_file": null,
      "notes": "Key=option4 (4)."
    },
    {
      "n": 2,
      "type_id": 1,
      "question": "28 371 rounded to the nearest hundred is [?].",
      "answer0": "28 400",
      "answer1": "28 370",
      "answer2": "28 300",
      "answer3": "28 000",
      "correct_answer": 0,
      "skill_id": 109,
      "difficulty_id": 1,
      "explanation": "Look at the tens digit of 28 371, which is 7. Since 7 >= 5, round the hundreds digit up: 3 -> 4. So 28 371 rounds to 28 400. Answer: 28 400 (option 1).",
      "hints": ["Look at the tens digit to decide rounding.", "Tens digit 7 means round up."],
      "source": "Henry Park 2022 P4 Semestral Assessment 2 Q2",
      "image_needed": false,
      "image_options": false,
      "image_file": null,
      "notes": "Key=option1 (28 400)."
    },
    {
      "n": 3,
      "type_id": 1,
      "question": "What fraction of the shapes in the box are crosses?",
      "answer0": "3/9",
      "answer1": "3/12",
      "answer2": "9/12",
      "answer3": "9/3",
      "correct_answer": 1,
      "skill_id": 120,
      "difficulty_id": 1,
      "explanation": "The box has 12 shapes in total (2 rows of 6). There are 3 crosses. So the fraction that are crosses is 3/12. Answer: 3/12 (option 2).",
      "hints": ["Count the total number of shapes.", "Count how many are crosses, then write as a fraction of the total."],
      "source": "Henry Park 2022 P4 Semestral Assessment 2 Q3",
      "image_needed": true,
      "image_options": false,
      "image_file": "q3.png",
      "image_page": 3,
      "image_bbox": [0.43, 0.61, 0.74, 0.73],
      "image_loc": "right of the question, a boxed array of 12 shapes (crosses and hearts), 2 rows of 6",
      "notes": "Stem stripped of directional 'in the box'; figure shows 3 crosses + 9 hearts = 12 shapes. Key=option2 (3/12)."
    },
    {
      "n": 4,
      "type_id": 1,
      "question": "Write 4 8/25 as a decimal.",
      "answer0": "4.032",
      "answer1": "4.08",
      "answer2": "4.32",
      "answer3": "4.88",
      "correct_answer": 2,
      "skill_id": 127,
      "difficulty_id": 2,
      "explanation": "Convert 8/25 to a decimal by making the denominator 100: 8/25 = 32/100 = 0.32. So 4 8/25 = 4.32. Answer: 4.32 (option 3).",
      "hints": ["Make the denominator 100: multiply top and bottom by 4.", "8/25 = 32/100 = 0.32."],
      "source": "Henry Park 2022 P4 Semestral Assessment 2 Q4",
      "image_needed": false,
      "image_options": false,
      "image_file": null,
      "notes": "Key=option3 (4.32)."
    },
    {
      "n": 5,
      "type_id": 1,
      "question": "The digit 5 in 7.654 stands for 5 [?].",
      "answer0": "ones",
      "answer1": "tens",
      "answer2": "tenths",
      "answer3": "hundredths",
      "correct_answer": 3,
      "skill_id": 123,
      "difficulty_id": 1,
      "explanation": "In 7.654 the digits after the decimal point are tenths (6), hundredths (5), thousandths (4). The digit 5 is in the hundredths place, so it stands for 5 hundredths. Answer: hundredths (option 4).",
      "hints": ["After the decimal point: tenths, hundredths, thousandths.", "5 is the second digit after the point."],
      "source": "Henry Park 2022 P4 Semestral Assessment 2 Q5",
      "image_needed": false,
      "image_options": false,
      "image_file": null,
      "notes": "Key=option4 (hundredths)."
    },
    {
      "n": 6,
      "type_id": 1,
      "question": "In the figure, which angle is smaller than a right angle?",
      "answer0": "angle a",
      "answer1": "angle b",
      "answer2": "angle c",
      "answer3": "angle d",
      "correct_answer": 3,
      "skill_id": 140,
      "difficulty_id": 2,
      "explanation": "A right angle is 90 degrees. Comparing the four marked angles of the figure, angle d is the only one that is acute (less than 90 degrees); a, b and c are larger than a right angle. Answer: angle d (option 4).",
      "hints": ["A right angle is 90 degrees (a square corner).", "An acute angle looks 'narrower' than a square corner."],
      "source": "Henry Park 2022 P4 Semestral Assessment 2 Q6",
      "image_needed": true,
      "image_options": false,
      "image_file": "q6.png",
      "image_page": 4,
      "image_bbox": [0.30, 0.55, 0.56, 0.72],
      "image_loc": "below the question, an irregular pentagon-like figure with angles labelled a, b, c, d",
      "notes": "Stem stripped of 'below'. Key=option4 (angle d)."
    },
    {
      "n": 7,
      "type_id": 1,
      "question": "Find the perimeter of the rectangle.",
      "answer0": "184 cm",
      "answer1": "62 cm",
      "answer2": "60 cm",
      "answer3": "31 cm",
      "correct_answer": 1,
      "skill_id": 143,
      "difficulty_id": 1,
      "explanation": "Perimeter of a rectangle = 2 x (length + breadth) = 2 x (23 + 8) = 2 x 31 = 62 cm. Answer: 62 cm (option 2).",
      "hints": ["Perimeter = 2 x (length + breadth).", "23 + 8 = 31, then double it."],
      "source": "Henry Park 2022 P4 Semestral Assessment 2 Q7",
      "image_needed": true,
      "image_options": false,
      "image_file": "q7.png",
      "image_page": 5,
      "image_bbox": [0.20, 0.16, 0.62, 0.27],
      "image_loc": "below the question, a rectangle labelled 23 cm (top) and 8 cm (right side)",
      "notes": "Stem stripped of 'shown below'. Key=option2 (62 cm)."
    },
    {
      "n": 8,
      "type_id": 1,
      "question": "The bar graph shows the number of books borrowed by a group of students from Monday to Friday. On which day did the students borrow twice as many books as Monday?",
      "answer0": "Tuesday",
      "answer1": "Wednesday",
      "answer2": "Thursday",
      "answer3": "Friday",
      "correct_answer": 3,
      "skill_id": 102,
      "difficulty_id": 2,
      "explanation": "From the graph, Monday = about 23 books. Twice Monday is about 46 books. Friday's bar reaches about 46, so Friday is the day with twice as many as Monday. Answer: Friday (option 4).",
      "hints": ["Read Monday's value first.", "Find the day whose bar is double Monday's value."],
      "source": "Henry Park 2022 P4 Semestral Assessment 2 Q8",
      "image_needed": true,
      "image_options": false,
      "image_file": "q8.png",
      "image_page": 5,
      "image_bbox": [0.18, 0.45, 0.80, 0.68],
      "image_loc": "below the first line of the question, a bar graph of books borrowed Mon-Fri",
      "notes": "Stem stripped of 'below'. Mon~23, Fri~46. Key=option4 (Friday)."
    },
    {
      "n": 9,
      "type_id": 1,
      "question": "Joyce bought 2/5 m of red ribbon. She also bought a roll of yellow ribbon which was 3/4 m longer than the red ribbon. How many metres of yellow ribbon did she buy?",
      "answer0": "5/9 m",
      "answer1": "7/20 m",
      "answer2": "1 3/20 m",
      "answer3": "1 11/20 m",
      "correct_answer": 2,
      "skill_id": 121,
      "difficulty_id": 2,
      "explanation": "Yellow = red + 3/4 = 2/5 + 3/4. Common denominator 20: 2/5 = 8/20, 3/4 = 15/20. Sum = 23/20 = 1 3/20 m. Answer: 1 3/20 m (option 3).",
      "hints": ["Yellow = 2/5 + 3/4.", "Use a common denominator of 20."],
      "source": "Henry Park 2022 P4 Semestral Assessment 2 Q9",
      "image_needed": false,
      "image_options": false,
      "image_file": null,
      "notes": "Key=option3 (1 3/20 m)."
    },
    {
      "n": 10,
      "type_id": 1,
      "question": "Four different shapes J, K, L and M are shown. Which of the following figure(s) are symmetrical?",
      "answer0": "J and K only",
      "answer1": "J, K and L only",
      "answer2": "J, K and M only",
      "answer3": "J, K, L and M",
      "correct_answer": 1,
      "skill_id": 144,
      "difficulty_id": 2,
      "explanation": "J (isosceles triangle), K (isosceles triangle) and L (rectangle) each have a line of symmetry. M is a slanted parallelogram/trapezium with no line of symmetry. So the symmetrical figures are J, K and L only. Answer: J, K and L only (option 2).",
      "hints": ["A figure is symmetric if a fold line gives two matching halves.", "A slanted parallelogram has no line of symmetry."],
      "source": "Henry Park 2022 P4 Semestral Assessment 2 Q10",
      "image_needed": true,
      "image_options": false,
      "image_file": "q10.png",
      "image_page": 6,
      "image_bbox": [0.19, 0.46, 0.80, 0.58],
      "image_loc": "below the question, four grid shapes labelled J, K, L, M",
      "notes": "Stem stripped of 'below'. Key=option2 (J, K and L only)."
    },
    {
      "n": 11,
      "type_id": 2,
      "question": "What is the remainder when 8022 is divided by 8?",
      "answer0": "6",
      "answer1": null,
      "answer2": null,
      "answer3": null,
      "correct_answer": null,
      "skill_id": 117,
      "difficulty_id": 2,
      "explanation": "8022 / 8 = 1002 remainder 6 (since 8 x 1002 = 8016, and 8022 - 8016 = 6). The remainder is 6.",
      "hints": ["Divide 8022 by 8 using long division.", "8 x 1002 = 8016; 8022 - 8016 = 6."],
      "source": "Henry Park 2022 P4 Semestral Assessment 2 Q11",
      "image_needed": false,
      "image_options": false,
      "image_file": null,
      "notes": "Key=6."
    },
    {
      "n": 12,
      "type_id": 2,
      "question": "3180 × 7 = [?]",
      "answer0": "22260",
      "answer1": null,
      "answer2": null,
      "answer3": null,
      "correct_answer": null,
      "skill_id": 116,
      "difficulty_id": 1,
      "explanation": "3180 x 7: 3000 x 7 = 21000, 180 x 7 = 1260, total = 21000 + 1260 = 22260.",
      "hints": ["Multiply each part: 3000 x 7 and 180 x 7.", "Add the partial products."],
      "source": "Henry Park 2022 P4 Semestral Assessment 2 Q12",
      "image_needed": false,
      "image_options": false,
      "image_file": null,
      "notes": "Key=22260."
    },
    {
      "n": 13,
      "type_id": 2,
      "question": "Three factors of 16 are 1, 4 and 16. What are the other two factors of 16?",
      "answer0": "2",
      "answer1": "8",
      "answer2": null,
      "answer3": null,
      "correct_answer": null,
      "skill_id": 111,
      "difficulty_id": 1,
      "explanation": "The factors of 16 are 1, 2, 4, 8 and 16. Given 1, 4 and 16, the other two factors are 2 and 8.",
      "hints": ["List all numbers that divide 16 exactly.", "Factors: 1, 2, 4, 8, 16."],
      "source": "Henry Park 2022 P4 Semestral Assessment 2 Q13",
      "image_needed": false,
      "image_options": false,
      "image_file": null,
      "notes": "Numeric two-blank answer; original prints 'Three factors of 16 is'. Key=2 and 8 (answer0=2, answer1=8)."
    },
    {
      "n": 14,
      "type_id": 2,
      "question": "Express 10/12 in its simplest form.",
      "answer0": "5/6",
      "answer1": null,
      "answer2": null,
      "answer3": null,
      "correct_answer": null,
      "skill_id": 119,
      "difficulty_id": 1,
      "explanation": "Divide numerator and denominator by their common factor 2: 10/12 = (10/2)/(12/2) = 5/6.",
      "hints": ["Find a common factor of 10 and 12.", "Divide both by 2."],
      "source": "Henry Park 2022 P4 Semestral Assessment 2 Q14",
      "image_needed": false,
      "image_options": false,
      "image_file": null,
      "notes": "Key=5/6."
    },
    {
      "n": 15,
      "type_id": 2,
      "question": "Write 2 3/4 as an improper fraction.",
      "answer0": "11/4",
      "answer1": null,
      "answer2": null,
      "answer3": null,
      "correct_answer": null,
      "skill_id": 119,
      "difficulty_id": 1,
      "explanation": "2 3/4 = (2 x 4 + 3)/4 = (8 + 3)/4 = 11/4.",
      "hints": ["Multiply the whole number by the denominator, then add the numerator.", "2 x 4 + 3 = 11, over 4."],
      "source": "Henry Park 2022 P4 Semestral Assessment 2 Q15",
      "image_needed": false,
      "image_options": false,
      "image_file": null,
      "notes": "Key=11/4."
    },
    {
      "n": 16,
      "type_id": 2,
      "question": "What is the value of 3/5 + 3/7 ? Express your answer as a mixed number.",
      "answer0": "1 1/35",
      "answer1": null,
      "answer2": null,
      "answer3": null,
      "correct_answer": null,
      "skill_id": 121,
      "difficulty_id": 2,
      "explanation": "Common denominator 35: 3/5 = 21/35, 3/7 = 15/35. Sum = 36/35 = 1 1/35.",
      "hints": ["Use a common denominator of 35.", "21/35 + 15/35 = 36/35."],
      "source": "Henry Park 2022 P4 Semestral Assessment 2 Q16",
      "image_needed": false,
      "image_options": false,
      "image_file": null,
      "notes": "Key=1 1/35."
    },
    {
      "n": 17,
      "type_id": 2,
      "question": "Arrange the following numbers in order from the greatest to the smallest. 0.102 , 0.021 , 0.201",
      "answer0": "0.201",
      "answer1": "0.102",
      "answer2": "0.021",
      "answer3": null,
      "correct_answer": null,
      "skill_id": 124,
      "difficulty_id": 2,
      "explanation": "Compare tenths first: 0.201 has 2 tenths, 0.102 has 1 tenth, 0.021 has 0 tenths. So greatest to smallest: 0.201, 0.102, 0.021.",
      "hints": ["Compare the tenths digit first.", "Greatest tenths = greatest number."],
      "source": "Henry Park 2022 P4 Semestral Assessment 2 Q17",
      "image_needed": false,
      "image_options": false,
      "image_file": null,
      "notes": "Ordering task -> FIB, greatest to smallest. Key=0.201, 0.102, 0.021."
    },
    {
      "n": 18,
      "type_id": 2,
      "question": "0.6 = 6/[?]",
      "answer0": "10",
      "answer1": null,
      "answer2": null,
      "answer3": null,
      "correct_answer": null,
      "skill_id": 126,
      "difficulty_id": 1,
      "explanation": "0.6 means 6 tenths = 6/10. So the missing number in the box is 10.",
      "hints": ["0.6 is read as 6 tenths.", "Tenths means denominator 10."],
      "source": "Henry Park 2022 P4 Semestral Assessment 2 Q18",
      "image_needed": false,
      "image_options": false,
      "image_file": null,
      "notes": "Key=10."
    },
    {
      "n": 19,
      "type_id": 2,
      "question": "PQRS is a rectangle. Find angle q.",
      "answer0": "67",
      "answer1": null,
      "answer2": null,
      "answer3": null,
      "correct_answer": null,
      "skill_id": 143,
      "difficulty_id": 2,
      "explanation": "In rectangle PQRS, angle PQR = 90 degrees. The diagonal QS makes a 23 degree angle with QR. So angle q (PQS) = 90 - 23 = 67 degrees.",
      "hints": ["Each corner of a rectangle is 90 degrees.", "Angle q = 90 - 23."],
      "source": "Henry Park 2022 P4 Semestral Assessment 2 Q19",
      "image_needed": true,
      "image_options": false,
      "image_file": "q19.png",
      "image_page": 9,
      "image_bbox": [0.19, 0.58, 0.52, 0.74],
      "image_loc": "below the question, rectangle PQRS with diagonal QS, angle q at Q and 23 degrees marked",
      "notes": "Answer in degrees. Key=67 degrees."
    },
    {
      "n": 20,
      "type_id": 2,
      "question": "The square has an area of 36 cm². Find the perimeter of the square.",
      "answer0": "24",
      "answer1": null,
      "answer2": null,
      "answer3": null,
      "correct_answer": null,
      "skill_id": 137,
      "difficulty_id": 2,
      "explanation": "Area of a square = side x side = 36, so side = 6 cm (6 x 6 = 36). Perimeter = 4 x side = 4 x 6 = 24 cm.",
      "hints": ["Find the side: side x side = 36.", "Perimeter = 4 x side."],
      "source": "Henry Park 2022 P4 Semestral Assessment 2 Q20",
      "image_needed": true,
      "image_options": false,
      "image_file": "q20.png",
      "image_page": 10,
      "image_bbox": [0.40, 0.18, 0.56, 0.29],
      "image_loc": "below the question, a shaded square labelled 36 cm squared",
      "notes": "Stem stripped of 'shown below'; answer in cm. Key=24 cm."
    },
    {
      "n": 21,
      "type_id": 2,
      "question": "The line graph shows Aru's mass each year from 2014 to 2018. What was the difference in Aru's mass between 2015 and 2016?",
      "answer0": "8",
      "answer1": null,
      "answer2": null,
      "answer3": null,
      "correct_answer": null,
      "skill_id": 147,
      "difficulty_id": 2,
      "explanation": "From the graph, Aru's mass in 2015 was 54 kg and in 2016 was 62 kg. Difference = 62 - 54 = 8 kg.",
      "hints": ["Read the mass at 2015 and at 2016.", "Subtract the smaller from the larger."],
      "source": "Henry Park 2022 P4 Semestral Assessment 2 Q21",
      "image_needed": true,
      "image_options": false,
      "image_file": "q21.png",
      "image_page": 10,
      "image_bbox": [0.17, 0.39, 0.78, 0.68],
      "image_loc": "below the question, a line graph of mass (kg) vs year 2014-2018",
      "notes": "Answer in kg; answer key shows 62-54=8kg. Key=8 kg."
    },
    {
      "n": 22,
      "type_id": 2,
      "question": "Kelly has 2168 beads. Grace has 840 beads. How many beads must Kelly give to Grace so that they have an equal number of beads?",
      "answer0": "664",
      "answer1": null,
      "answer2": null,
      "answer3": null,
      "correct_answer": null,
      "skill_id": 118,
      "difficulty_id": 2,
      "explanation": "Total beads = 2168 + 840 = 3008. Equal share = 3008 / 2 = 1504. Kelly must give 2168 - 1504 = 664 beads. (Equivalently, the difference 2168 - 840 = 1328, halved = 664.)",
      "hints": ["Find the difference between the two amounts.", "Give away half the difference."],
      "source": "Henry Park 2022 P4 Semestral Assessment 2 Q22",
      "image_needed": false,
      "image_options": false,
      "image_file": null,
      "notes": "Key=664 (2168-840=1328, 1328/2=664)."
    },
    {
      "n": 23,
      "type_id": 2,
      "question": "[?] hundredths ÷ 2 = 0.14",
      "answer0": "28",
      "answer1": null,
      "answer2": null,
      "answer3": null,
      "correct_answer": null,
      "skill_id": 130,
      "difficulty_id": 2,
      "explanation": "0.14 = 14 hundredths. Since (the box) hundredths divided by 2 = 14 hundredths, the box = 14 x 2 = 28 hundredths. So the missing number is 28.",
      "hints": ["0.14 means 14 hundredths.", "Work backwards: 14 x 2 = 28."],
      "source": "Henry Park 2022 P4 Semestral Assessment 2 Q23",
      "image_needed": false,
      "image_options": false,
      "image_file": null,
      "notes": "Key=28."
    },
    {
      "n": 24,
      "type_id": 2,
      "question": "Muthu used 12.6 ℓ of red paint. Kim used 3.8 ℓ of red paint more than Muthu. How much red paint did Muthu and Kim use altogether?",
      "answer0": "29",
      "answer1": null,
      "answer2": null,
      "answer3": null,
      "correct_answer": null,
      "skill_id": 131,
      "difficulty_id": 2,
      "explanation": "Kim used 12.6 + 3.8 = 16.4 litres. Altogether = 16.4 + 12.6 = 29 litres.",
      "hints": ["Find Kim's amount: 12.6 + 3.8.", "Add both amounts together."],
      "source": "Henry Park 2022 P4 Semestral Assessment 2 Q24",
      "image_needed": false,
      "image_options": false,
      "image_file": null,
      "notes": "Answer in litres. Key=29 litres (Kim 16.4 + Muthu 12.6)."
    },
    {
      "n": 25,
      "type_id": 0,
      "question": "(a) Shade 2 more squares to form a symmetric figure with AB as the line of symmetry. (b) Complete the symmetric figure with CD as the line of symmetry.",
      "answer0": null,
      "answer1": null,
      "answer2": null,
      "answer3": null,
      "correct_answer": null,
      "skill_id": 145,
      "difficulty_id": 2,
      "explanation": "(a) Shade the two squares that mirror the existing shaded squares across the diagonal AB so the pattern is symmetric about AB. (b) Reflect the given half-figure across line CD to complete the symmetric figure (the lower half mirrors the upper half).",
      "hints": ["Reflect each shaded square across the line of symmetry.", "Points equidistant from the mirror line on both sides match."],
      "source": "Henry Park 2022 P4 Semestral Assessment 2 Q25",
      "image_needed": true,
      "image_options": false,
      "image_file": "q25.png",
      "image_page": 12,
      "image_bbox": [0.18, 0.20, 0.62, 0.78],
      "image_loc": "two grids: (a) shaded 6x6 grid with diagonal AB, (b) dot grid with half-figure and line CD",
      "notes": "Interactive shade/draw task -> type_id 0 (skipped on insert). Answer: reflect across the line of symmetry."
    },
    {
      "n": 26,
      "type_id": 0,
      "question": "(a) Marcus is standing at point A. He follows the directions: (i) Walk 5 metres towards South. (ii) Turn 90 degrees clockwise. (iii) Walk straight for 7 metres. Mark a cross (X) on the grid to show where Marcus will be. (b) Valerie walked directly from point B to point A in a straight line. In which direction did Valerie walk?",
      "answer0": null,
      "answer1": null,
      "answer2": null,
      "answer3": null,
      "correct_answer": null,
      "skill_id": 142,
      "difficulty_id": 2,
      "explanation": "(a) From A, walk 5 m South, then turn 90 degrees clockwise (now facing West) and walk 7 m West; mark X there. (b) B is to the North-East of A, so walking from B to A is in the South-West direction.",
      "hints": ["After facing South, a 90 degree clockwise turn faces West.", "From B to A, look at the compass: B is North-East of A."],
      "source": "Henry Park 2022 P4 Semestral Assessment 2 Q26",
      "image_needed": true,
      "image_options": false,
      "image_file": "q26.png",
      "image_page": 13,
      "image_bbox": [0.19, 0.32, 0.78, 0.70],
      "image_loc": "a square grid with points A and B marked and a North arrow with 1 m scale",
      "notes": "Part (a) is mark-a-cross (interactive); part (b) answer = South-West. type_id 0 (mixed interactive). Key (b)=South-West."
    },
    {
      "n": 27,
      "type_id": 0,
      "question": "Draw a line perpendicular to KL passing through point Y on the grid and label it.",
      "answer0": null,
      "answer1": null,
      "answer2": null,
      "answer3": null,
      "correct_answer": null,
      "skill_id": 100,
      "difficulty_id": 2,
      "explanation": "Line KL runs diagonally up to the right. A line perpendicular to KL meets it at a right angle (90 degrees); draw such a line through point Y and label it.",
      "hints": ["Perpendicular lines meet at a right angle.", "On a grid, a line going one way and another at 90 degrees to it are perpendicular."],
      "source": "Henry Park 2022 P4 Semestral Assessment 2 Q27",
      "image_needed": true,
      "image_options": false,
      "image_file": "q27.png",
      "image_page": 14,
      "image_bbox": [0.27, 0.20, 0.74, 0.45],
      "image_loc": "below the question, a grid with diagonal line KL and point Y above it",
      "notes": "Interactive draw task -> type_id 0 (skipped on insert). Note: skill 100 is a P3 perpendicular/parallel skill, nearest match."
    },
    {
      "n": 28,
      "type_id": 2,
      "question": "Tim and his brother took part in a 10-km run. They started running at 08 45. Tim took 2 h 20 min to complete the run while his brother was faster than him by 30 minutes. What time did Tim's brother complete the run? Give your answer using the 24-hour clock.",
      "answer0": "10 35",
      "answer1": null,
      "answer2": null,
      "answer3": null,
      "correct_answer": null,
      "skill_id": 135,
      "difficulty_id": 2,
      "explanation": "Brother's time taken = 2 h 20 min - 30 min = 1 h 50 min. Finish time = 08 45 + 1 h 50 min = 10 35. (The answer key adds 08 45 + 2 h then back-offs; final answer is 10 35.)",
      "hints": ["Brother is 30 min faster, so his duration is 1 h 50 min.", "Add 1 h 50 min to 08 45."],
      "source": "Henry Park 2022 P4 Semestral Assessment 2 Q28",
      "image_needed": false,
      "image_options": false,
      "image_file": null,
      "notes": "24-hour clock answer. Key=10 35."
    },
    {
      "n": 29,
      "type_id": 2,
      "question": "The bar graph shows the number of blueberry muffins sold by a stall over 5 weeks. The bar showing the number sold in Week 1 has not been drawn. What was the total number of blueberry muffins sold in Weeks 2 to 4?",
      "answer0": "225",
      "answer1": null,
      "answer2": null,
      "answer3": null,
      "correct_answer": null,
      "skill_id": 104,
      "difficulty_id": 2,
      "explanation": "From the graph: Week 2 = 40, Week 3 = 60, Week 4 = 120 (some read 45/60/120). Total Weeks 2 to 4 = 120 + 60 + 45 = 225 (per answer key).",
      "hints": ["Read the bars for Weeks 2, 3 and 4.", "Add the three values."],
      "source": "Henry Park 2022 P4 Semestral Assessment 2 Q29",
      "image_needed": true,
      "image_options": false,
      "image_file": "q29.png",
      "image_page": 15,
      "image_bbox": [0.20, 0.27, 0.78, 0.50],
      "image_loc": "below the question, a bar graph of blueberry muffins sold Weeks 1-5 (Week 1 bar blank)",
      "notes": "Key=225 (120+60+45). Read graph values per key."
    },
    {
      "n": 30,
      "type_id": 2,
      "question": "The total number of blueberry muffins sold in Week 2 and Week 5 is 4 times the number of muffins sold in Week 1. Find the number of blueberry muffins sold in Week 1.",
      "answer0": "30",
      "answer1": null,
      "answer2": null,
      "answer3": null,
      "correct_answer": null,
      "skill_id": 104,
      "difficulty_id": 2,
      "explanation": "Week 2 + Week 5 = 45 + 75 = 120. This equals 4 times Week 1, so Week 1 = 120 / 4 = 30 muffins.",
      "hints": ["Add the Week 2 and Week 5 values from the graph.", "Divide that total by 4."],
      "source": "Henry Park 2022 P4 Semestral Assessment 2 Q30",
      "image_needed": false,
      "image_options": false,
      "image_file": null,
      "notes": "Uses Q29 graph (Week2=45, Week5=75). Key=30 (45+75=120, 120/4=30)."
    },
    {
      "n": 31,
      "type_id": 2,
      "question": "2 similar plates cost as much as 3 similar bowls. George paid $60 for 4 such plates and 4 such bowls. How much must George pay if he buys only 5 bowls instead?",
      "answer0": "30",
      "answer1": null,
      "answer2": null,
      "answer3": null,
      "correct_answer": null,
      "skill_id": 118,
      "difficulty_id": 3,
      "explanation": "2 plates = 3 bowls, so 4 plates = 6 bowls. 4 plates + 4 bowls = 6 bowls + 4 bowls = 10 bowls = $60. So 1 bowl = $6 and 5 bowls = 5 x $6 = $30.",
      "hints": ["Convert plates into equivalent bowls (2 plates = 3 bowls).", "Find the total in 'bowls', then the cost of one bowl."],
      "source": "Henry Park 2022 P4 Semestral Assessment 2 Q31",
      "image_needed": false,
      "image_options": false,
      "image_file": null,
      "notes": "Answer in dollars. Key=$30 (10 bowls=$60, 1 bowl=$6, 5 bowls=$30)."
    },
    {
      "n": 32,
      "type_id": 2,
      "question": "4/6 of a number is 280. What is 1/3 of the same number?",
      "answer0": "140",
      "answer1": null,
      "answer2": null,
      "answer3": null,
      "correct_answer": null,
      "skill_id": 120,
      "difficulty_id": 2,
      "explanation": "4/6 (= 4 units) of the number is 280, so 1 unit (1/6) = 280 / 4 = 70. The number has 6 units. 1/3 = 2/6 = 2 units = 2 x 70 = 140.",
      "hints": ["Treat the number as 6 equal units; 4 units = 280.", "1/3 = 2/6 = 2 units."],
      "source": "Henry Park 2022 P4 Semestral Assessment 2 Q32",
      "image_needed": false,
      "image_options": false,
      "image_file": null,
      "notes": "Key=140 (1u=70, 2u=140)."
    },
    {
      "n": 33,
      "type_id": 2,
      "question": "Triangle A has a perimeter of 24.8 cm. Jensen used 2 such triangles and a square to form Figure K. Find the perimeter of Figure K.",
      "answer0": "49.6",
      "answer1": null,
      "answer2": null,
      "answer3": null,
      "correct_answer": null,
      "skill_id": 131,
      "difficulty_id": 3,
      "explanation": "When the 2 triangles and the square are joined to form Figure K, the square's sides coincide with triangle sides internally, so the outer perimeter is made up of the outer edges of the 2 triangles: 24.8 + 24.8 = 49.6 cm (per answer key).",
      "hints": ["Add the perimeters of the two triangles.", "Hidden (joined) edges do not count, giving 24.8 + 24.8."],
      "source": "Henry Park 2022 P4 Semestral Assessment 2 Q33",
      "image_needed": true,
      "image_options": false,
      "image_file": "q33.png",
      "image_page": 16,
      "image_bbox": [0.18, 0.55, 0.66, 0.78],
      "image_loc": "below the question, Triangle A on the left and Figure K (two triangles + square) on the right",
      "notes": "Answer in cm. Key=49.6 cm (24.8 + 24.8)."
    },
    {
      "n": 34,
      "type_id": 2,
      "question": "Matt placed different numbers of blocks A and B on the weighing scales. Find the mass of block B. Express your answer as a decimal.",
      "answer0": "0.1",
      "answer1": null,
      "answer2": null,
      "answer3": null,
      "correct_answer": null,
      "skill_id": 131,
      "difficulty_id": 3,
      "explanation": "Left scale: 1 block A reads 900 g, so A = 900 g. Right scale: 2 A + 2 B reads 2 kg = 2000 g. 2 A = 1800 g, so 2 B = 2000 - 1800 = 200 g, and 1 B = 100 g = 0.1 kg.",
      "hints": ["Read block A's mass from the first scale (in grams).", "Subtract the mass of the A blocks from the total on the second scale."],
      "source": "Henry Park 2022 P4 Semestral Assessment 2 Q34",
      "image_needed": true,
      "image_options": false,
      "image_file": "q34.png",
      "image_page": 17,
      "image_bbox": [0.22, 0.25, 0.78, 0.46],
      "image_loc": "two weighing scales: left shows block A (in g), right shows 2 A + 2 B (in kg)",
      "notes": "Answer in kg as a decimal. Key=0.1 kg (A=900g, 2A=1800g, 2B=200g, B=100g=0.1kg)."
    },
    {
      "n": 35,
      "type_id": 2,
      "question": "In the figure, ABCD and BEFG are squares and BKLC is a rectangle. AK and DL are straight lines. Find angle a.",
      "answer0": "135",
      "answer1": null,
      "answer2": null,
      "answer3": null,
      "correct_answer": null,
      "skill_id": 230,
      "difficulty_id": 3,
      "explanation": "Angle EBG of square BEFG is 90 degrees; with the 45 degree angle marked at B, angle GBC (or the relevant part) gives 90 - 45 = 45 degrees. Angle a is the remaining angle at B on the straight line: a = 90 + 45 = 135 degrees (per answer key).",
      "hints": ["Each angle of a square is 90 degrees.", "Use angles on a straight line: 90 - 45 = 45, then 90 + 45 = 135."],
      "source": "Henry Park 2022 P4 Semestral Assessment 2 Q35",
      "image_needed": true,
      "image_options": false,
      "image_file": "q35.png",
      "image_page": 17,
      "image_bbox": [0.19, 0.62, 0.62, 0.84],
      "image_loc": "below the question, two squares and a rectangle with angle a and a 45 degree angle marked at B",
      "notes": "Answer in degrees. Key=135 degrees (90-45=45, 90+45=135). skill 230 (P6 angles in figures) nearest; P4 has no combined-figure angle skill."
    },
    {
      "n": 36,
      "type_id": 2,
      "question": "Ahmad sold an equal number of apples and peaches. Each apple cost $2 while each peach cost $5. He collected a total of $756 from the sale of the fruits. (a) How many peaches were sold? (b) How much money was collected from the sales of apples?",
      "answer0": "108",
      "answer1": "216",
      "answer2": null,
      "answer3": null,
      "correct_answer": null,
      "skill_id": 118,
      "difficulty_id": 3,
      "explanation": "(a) 1 apple + 1 peach = $2 + $5 = $7 per matching pair. Number of each = $756 / $7 = 108 peaches (and 108 apples). (b) Money from apples = 108 x $2 = $216.",
      "hints": ["Each apple-peach pair costs $2 + $5 = $7.", "Divide $756 by $7 to find how many of each."],
      "source": "Henry Park 2022 P4 Semestral Assessment 2 Q36",
      "image_needed": false,
      "image_options": false,
      "image_file": null,
      "notes": "Two-part: answer0=(a) 108 peaches, answer1=(b) $216. Key: a=108, b=$216."
    },
    {
      "n": 37,
      "type_id": 2,
      "question": "The total age of Ben and his mother is 36 years old now. In 8 years' time, Ben's mother will be three times the age of Ben. What is Ben's age now?",
      "answer0": "5",
      "answer1": null,
      "answer2": null,
      "answer3": null,
      "correct_answer": null,
      "skill_id": 118,
      "difficulty_id": 3,
      "explanation": "In 8 years, both age 8, so their total = 36 + 8 + 8 = 52. Then mother = 3 x Ben, so 4 units = 52, 1 unit = 13. Ben in 8 years = 13, so Ben now = 13 - 8 = 5 years.",
      "hints": ["Find the total age in 8 years' time (add 8 to each person).", "Split into 4 equal units (Ben = 1, mother = 3)."],
      "source": "Henry Park 2022 P4 Semestral Assessment 2 Q37",
      "image_needed": false,
      "image_options": false,
      "image_file": null,
      "notes": "Answer in years. Key=5 years (4u=52, 1u=13, 13-8=5)."
    },
    {
      "n": 38,
      "type_id": 2,
      "question": "The table shows the entrance fees for the Colourful Flower Exhibition. Adult: Weekday $13.90, Weekend $15.90. Child (3 to 12 years old): Weekday $6, Weekend $8. (a) On Saturday, Mr Chandra and his four-year-old child visited the exhibition. How much did Mr Chandra pay for the entrance fees altogether? (b) On Wednesday, Ms Sim brought a group of Primary 4 students. They paid a total of $241.90 to enter. How many students did Ms Sim bring?",
      "answer0": "23.90",
      "answer1": "38",
      "answer2": null,
      "answer3": null,
      "correct_answer": null,
      "skill_id": 131,
      "difficulty_id": 3,
      "explanation": "(a) Saturday is a weekend: adult $15.90 + child $8 = $23.90. (b) Wednesday is a weekday. Ms Sim (adult) pays $13.90, so students pay $241.90 - $13.90 = $228. Each child weekday fee is $6, so number of students = $228 / $6 = 38.",
      "hints": ["Saturday = weekend rates; Wednesday = weekday rates.", "Subtract Ms Sim's adult fee first, then divide by the child fee."],
      "source": "Henry Park 2022 P4 Semestral Assessment 2 Q38",
      "image_needed": true,
      "image_options": false,
      "image_file": "q38.png",
      "image_page": 20,
      "image_bbox": [0.24, 0.18, 0.74, 0.26],
      "image_loc": "below the first line, a 3-column table (blank/Weekday/Weekend) with Adult and Child rows",
      "notes": "Two-part: answer0=(a) $23.90, answer1=(b) 38 students. Key: a=$23.90, b=38."
    },
    {
      "n": 39,
      "type_id": 2,
      "question": "The figure shows Marcus's backyard with 2 identical 8-m square ponds. (a) What is the total area of the two square ponds? (b) What is the remaining area of the empty space around the two ponds in the backyard?",
      "answer0": "128",
      "answer1": "172",
      "answer2": null,
      "answer3": null,
      "correct_answer": null,
      "skill_id": 138,
      "difficulty_id": 3,
      "explanation": "(a) Each pond = 8 m x 8 m = 64 m squared. Two ponds = 2 x 64 = 128 m squared. (b) Backyard area = 20 m x 15 m = 300 m squared. Remaining = 300 - 128 = 172 m squared.",
      "hints": ["Area of a square pond = side x side.", "Backyard area = 20 x 15, then subtract the ponds."],
      "source": "Henry Park 2022 P4 Semestral Assessment 2 Q39",
      "image_needed": true,
      "image_options": false,
      "image_file": "q39.png",
      "image_page": 21,
      "image_bbox": [0.24, 0.21, 0.62, 0.40],
      "image_loc": "below the question, a 20 m x 15 m rectangle containing two shaded 8 m square ponds",
      "notes": "Two-part: answer0=(a) 128 m squared, answer1=(b) 172 m squared. Key: a=128m2, b=172m2."
    },
    {
      "n": 40,
      "type_id": 2,
      "question": "Cheryl started cooking dinner at 17 35. She spent 1 h 10 min to cook the dinner. After that, she cleaned up her kitchen before having her dinner at 19 10. (a) How long did she take to clean up the kitchen? (b) After dinner, Cheryl watched a movie that lasted for 135 minutes. She finished watching the movie at 22 30. What time did she start watching the movie? Give your answer using the 12-hour clock.",
      "answer0": "25 min",
      "answer1": "10.15 p.m.",
      "answer2": null,
      "answer3": null,
      "correct_answer": null,
      "skill_id": 135,
      "difficulty_id": 3,
      "explanation": "(a) Cooking finished at 17 35 + 1 h 10 min = 18 45. She ate at 19 10, so cleaning took 19 10 - 18 45 = 25 min. (b) 135 min = 2 h 15 min. Start = 22 30 - 2 h 15 min = 20 15 = 10.15 p.m.",
      "hints": ["(a) Find when cooking ended, then to dinner time.", "(b) 135 min = 2 h 15 min; subtract from 22 30, then convert to 12-hour."],
      "source": "Henry Park 2022 P4 Semestral Assessment 2 Q40",
      "image_needed": false,
      "image_options": false,
      "image_file": null,
      "notes": "Two-part: answer0=(a) 25 min, answer1=(b) 10.15 p.m. Key: a=25min, b=10 30p.m. per key but 22 30 - 2h15min = 20 15 = 10.15 p.m.; answer key's '10 30 p.m.' is an arithmetic slip (it wrote 22 30 = 10 30 p.m. as the FINISH time, not start). Correct start = 10.15 p.m."
    },
    {
      "n": 41,
      "type_id": 2,
      "question": "Mrs Lim had an equal number of coins in each of the 25 glass jars. The next day, she broke 3 of the jars filled with coins. She threw away the broken jars and placed all the coins from the broken jars into the remaining jars equally. As a result, the number of coins in each of the remaining jars increased by 15. What was the total number of coins Mrs Lim had?",
      "answer0": "2750",
      "answer1": null,
      "answer2": null,
      "answer3": null,
      "correct_answer": null,
      "skill_id": 118,
      "difficulty_id": 3,
      "explanation": "Remaining jars = 25 - 3 = 22. The coins from 3 jars are spread over 22 jars, raising each by 15, so coins added = 22 x 15 = 330. These came from 3 jars, so each jar had 330 / 3 = 110 coins. Total = 110 x 25 = 2750 coins.",
      "hints": ["22 jars each gain 15 coins: 22 x 15 = 330 coins from the broken jars.", "Those 330 coins came from 3 jars; find coins per jar, then x 25."],
      "source": "Henry Park 2022 P4 Semestral Assessment 2 Q41",
      "image_needed": false,
      "image_options": false,
      "image_file": null,
      "notes": "Key=2750 (22x15=330, 330/3=110, 110x25=2750)."
    },
    {
      "n": 42,
      "type_id": 2,
      "question": "Mary kept some marbles in a box. 1/6 of the marbles were blue and the rest were red. After Mary put another 140 blue marbles into the box, 1/2 of the marbles in the box were blue. What was the total number of marbles in the box at first?",
      "answer0": "210",
      "answer1": null,
      "answer2": null,
      "answer3": null,
      "correct_answer": null,
      "skill_id": 122,
      "difficulty_id": 3,
      "explanation": "Red marbles stay the same. At first red = 5/6 of total. After adding 140 blue, blue = 1/2, so red = 1/2 = blue. The 5 units of red (out of 6) now equal the new blue count. The 4 'extra' units come from the 140 added: 4 units = 140, so 1 unit = 35. Total at first = 6 units = 6 x 35 = 210 marbles.",
      "hints": ["The red marbles never change; use them as the anchor.", "Adding 140 blue makes blue = red; that gain equals 4 units = 140."],
      "source": "Henry Park 2022 P4 Semestral Assessment 2 Q42",
      "image_needed": false,
      "image_options": false,
      "image_file": null,
      "notes": "Key=210 (4u=140, 1u=35, 6u=210)."
    },
    {
      "n": 43,
      "type_id": 2,
      "question": "Barry has a garden with an area of 216 m². It is made up of a rectangle and a square. The area of the rectangle is 5 times the area of the square. Barry wants to build a fence around part of his garden as indicated by the dotted line in the figure. Given that the breadth of the rectangle is 9 m, how many metres of fence does he need?",
      "answer0": "64",
      "answer1": null,
      "answer2": null,
      "answer3": null,
      "correct_answer": null,
      "skill_id": 138,
      "difficulty_id": 3,
      "explanation": "Total area = 6 units (5 for rectangle + 1 for square) = 216, so 1 unit = 36 m squared; the square has area 36 (side 6 m) and the rectangle 180 m squared. Rectangle length = 180 / 9 = 20 m. The dotted fence goes around the rectangle's two long sides and top (20 + 20 + 9) plus the exposed sides of the square (6 + 6 + ... ): 20 + 20 + 9 + 9 + 6 = 64 m (per answer key).",
      "hints": ["Split 216 into 6 equal units (square = 1, rectangle = 5).", "Square side = 6 m; rectangle length = 180 / 9 = 20 m; add the fenced edges."],
      "source": "Henry Park 2022 P4 Semestral Assessment 2 Q43",
      "image_needed": true,
      "image_options": false,
      "image_file": "q43.png",
      "image_page": 25,
      "image_bbox": [0.26, 0.24, 0.66, 0.42],
      "image_loc": "below the question, a long rectangle (9 m breadth) with a small square attached at the bottom, dotted fence outline",
      "notes": "Answer in metres. Key=64 m (1u=36, square side 6, rect length 20, 20+20+9+9+6=64)."
    }
  ]
}