{
 "paper": {
  "school": "Nan Chiau Primary School",
  "year": 2025,
  "level": "P4",
  "label": "End-of-Year Exam",
  "source_prefix": "Nan Chiau 2025 P4 End-of-Year Exam",
  "has_answer_key": true
 },
 "questions": [
  {
   "n": 1,
   "type_id": 1,
   "question": "80 000 + 6000 + 400 + 2 = [?]",
   "answer0": "86 420",
   "answer1": "86 402",
   "answer2": "86 042",
   "answer3": "80 642",
   "correct_answer": 1,
   "skill_id": 105,
   "difficulty_id": 1,
   "explanation": "Expanded form: 80 000 + 6000 + 400 + 2 = 86 402.",
   "hints": [
    "Add the place values: ten thousands, thousands, hundreds, ones.",
    "There are no tens, so the tens digit is 0."
   ],
   "source": "Nan Chiau 2025 P4 End-of-Year Exam Q1",
   "image_needed": false,
   "image_options": false,
   "image_file": null,
   "notes": "Key: option (2) 86 402. Note the stem itself shows a display blank '[?]' which IS the answer-entry for this MCQ; options supplied so kept as MCQ."
  },
  {
   "n": 2,
   "type_id": 1,
   "question": "Thirty-two thousand and forty-six in figures is [?]",
   "answer0": "32 460",
   "answer1": "32 406",
   "answer2": "32 046",
   "answer3": "3246",
   "correct_answer": 2,
   "skill_id": 106,
   "difficulty_id": 1,
   "explanation": "Thirty-two thousand = 32 000; forty-six = 46. Together: 32 046.",
   "hints": [
    "Write the thousands part first: 32 thousand = 32 000.",
    "Then add forty-six in the tens and ones places."
   ],
   "source": "Nan Chiau 2025 P4 End-of-Year Exam Q2",
   "image_needed": false,
   "image_options": false,
   "image_file": null,
   "notes": "Key: option (3) 32 046."
  },
  {
   "n": 3,
   "type_id": 1,
   "question": "In 14.27, the digit [?] is in the tenths place.",
   "answer0": "1",
   "answer1": "2",
   "answer2": "7",
   "answer3": "4",
   "correct_answer": 1,
   "skill_id": 123,
   "difficulty_id": 1,
   "explanation": "In 14.27, the first digit after the decimal point (2) is in the tenths place.",
   "hints": [
    "The tenths place is the first digit immediately after the decimal point.",
    "14.27 → the digit right after the point is 2."
   ],
   "source": "Nan Chiau 2025 P4 End-of-Year Exam Q3",
   "image_needed": false,
   "image_options": false,
   "image_file": null,
   "notes": "Key: option (2) = 2."
  },
  {
   "n": 4,
   "type_id": 1,
   "question": "5.06 + 2 = ?",
   "answer0": "5.08",
   "answer1": "5.26",
   "answer2": "7.06",
   "answer3": "7.26",
   "correct_answer": 2,
   "skill_id": 129,
   "difficulty_id": 1,
   "explanation": "Add 2 to the whole-number part: 5.06 + 2 = 7.06.",
   "hints": [
    "The 2 is a whole number, so add it to the ones place.",
    "The decimal part 0.06 stays the same."
   ],
   "source": "Nan Chiau 2025 P4 End-of-Year Exam Q4",
   "image_needed": false,
   "image_options": false,
   "image_file": null,
   "notes": "Key: option (3) 7.06."
  },
  {
   "n": 5,
   "type_id": 1,
   "question": "Which fraction is in its simplest form?",
   "answer0": "$$\\frac{4}{10}$$",
   "answer1": "$$\\frac{2}{8}$$",
   "answer2": "$$\\frac{3}{6}$$",
   "answer3": "$$\\frac{4}{9}$$",
   "correct_answer": 3,
   "skill_id": 78,
   "difficulty_id": 2,
   "explanation": "A fraction is in simplest form when numerator and denominator share no common factor other than 1. $$\\frac{4}{10}=\\frac{2}{5}$$, $$\\frac{2}{8}=\\frac{1}{4}$$, $$\\frac{3}{6}=\\frac{1}{2}$$; only $$\\frac{4}{9}$$ cannot be reduced.",
   "hints": [
    "Check whether the numerator and denominator share a common factor.",
    "4 and 9 have no common factor besides 1."
   ],
   "source": "Nan Chiau 2025 P4 End-of-Year Exam Q5",
   "image_needed": false,
   "image_options": false,
   "image_file": null,
   "notes": "Key: option (4) = 4/9."
  },
  {
   "n": 6,
   "type_id": 1,
   "question": "Which mixed number is represented by the letter A in the number line?",
   "answer0": "$$2\\frac{1}{4}$$",
   "answer1": "$$2\\frac{3}{4}$$",
   "answer2": "$$3\\frac{1}{4}$$",
   "answer3": "$$3\\frac{3}{4}$$",
   "correct_answer": 1,
   "skill_id": 119,
   "difficulty_id": 2,
   "explanation": "Each interval between whole numbers is divided into 4 equal parts (quarters). A sits 3 parts past 2, so A = 2 3/4.",
   "hints": [
    "Count how many equal parts each whole number is divided into.",
    "A is between 2 and 3, three small marks past 2."
   ],
   "source": "Nan Chiau 2025 P4 End-of-Year Exam Q6",
   "image_needed": true,
   "image_options": false,
   "image_file": "q6.png",
   "image_page": 3,
   "image_bbox": [
    0.18,
    0.42,
    0.74,
    0.55
   ],
   "image_loc": "number line from 0 to 3 with arrow labelled A near 2.75, upper-middle of page"
  },
  {
   "n": 7,
   "type_id": 1,
   "question": "Sally had 1 m 10 cm of string. She used 25 cm of it to tie a parcel. What is the length of the string she had left?",
   "answer0": "15 cm",
   "answer1": "45 cm",
   "answer2": "85 cm",
   "answer3": "135 cm",
   "correct_answer": 2,
   "skill_id": 87,
   "difficulty_id": 2,
   "explanation": "1 m 10 cm = 110 cm. 110 cm - 25 cm = 85 cm.",
   "hints": [
    "Convert 1 m 10 cm to centimetres first (100 + 10).",
    "Then subtract the 25 cm used."
   ],
   "source": "Nan Chiau 2025 P4 End-of-Year Exam Q7",
   "image_needed": false,
   "image_options": false,
   "image_file": null,
   "notes": "Key: option (3) 85 cm."
  },
  {
   "n": 8,
   "type_id": 1,
   "question": "The perimeter of a rectangle is 54 cm. Its length is 15 cm. Find its breadth.",
   "answer0": "12 cm",
   "answer1": "24 cm",
   "answer2": "27 cm",
   "answer3": "39 cm",
   "correct_answer": 0,
   "skill_id": 136,
   "difficulty_id": 2,
   "explanation": "Perimeter = 2 x (length + breadth). 54 = 2 x (15 + breadth), so 15 + breadth = 27, breadth = 12 cm.",
   "hints": [
    "Half the perimeter equals length + breadth.",
    "54 / 2 = 27; subtract the length 15."
   ],
   "source": "Nan Chiau 2025 P4 End-of-Year Exam Q8",
   "image_needed": true,
   "image_options": false,
   "image_file": "q8.png",
   "image_page": 4,
   "image_bbox": [
    0.22,
    0.47,
    0.58,
    0.66
   ],
   "image_loc": "rectangle diagram with length 15 cm marked on top and breadth shown as '?', middle of page"
  },
  {
   "n": 9,
   "type_id": 1,
   "question": "Metta bought an equal number of cupcakes and doughnuts. Find the least amount of money that she could have spent.<br>2 cupcakes for $7<br>5 doughnuts for $10",
   "answer0": "$14",
   "answer1": "$50",
   "answer2": "$55",
   "answer3": "$64",
   "correct_answer": 1,
   "skill_id": 118,
   "difficulty_id": 3,
   "explanation": "Equal numbers means the count is a common multiple of 2 and 5. Least common multiple = 10. For 10 cupcakes: 5 sets x $7 = $35; for 10 doughnuts: 2 sets x $10 = $20. Total = $35 + $20 = $55. (The least amount among the options that gives equal whole sets is $55.)",
   "hints": [
    "The number of cupcakes must equal the number of doughnuts; find the LCM of 2 and 5.",
    "Buy 10 of each: 5 x $7 plus 2 x $10."
   ],
   "source": "Nan Chiau 2025 P4 End-of-Year Exam Q9",
   "image_needed": true,
   "image_options": false,
   "image_file": "q9.png",
   "image_page": 5,
   "image_bbox": [
    0.22,
    0.2,
    0.72,
    0.3
   ],
   "image_loc": "two pictures: a box of cupcakes (2 for $7) and a box of doughnuts (5 for $10), upper-middle of page",
   "notes": "Key: option (3) $55."
  },
  {
   "n": 10,
   "type_id": 1,
   "question": "Anna had 2 kg of sugar. She packed them equally into 5 bags. How much sugar was there in each bag?",
   "answer0": "7 kg",
   "answer1": "2.5 kg",
   "answer2": "3 kg",
   "answer3": "0.4 kg",
   "correct_answer": 3,
   "skill_id": 125,
   "difficulty_id": 2,
   "explanation": "2 kg / 5 = 0.4 kg in each bag.",
   "hints": [
    "Divide the total mass by the number of bags.",
    "2 divided by 5 = 0.4."
   ],
   "source": "Nan Chiau 2025 P4 End-of-Year Exam Q10",
   "image_needed": false,
   "image_options": false,
   "image_file": null,
   "notes": "Key: option (4) 0.4 kg."
  },
  {
   "n": 11,
   "type_id": 1,
   "question": "Arrange the following fractions from the greatest to the smallest.<br>$$\\frac{3}{4}$$, $$\\frac{1}{2}$$, $$\\frac{5}{8}$$",
   "answer0": "$$\\frac{3}{4}$$, $$\\frac{5}{8}$$, $$\\frac{1}{2}$$",
   "answer1": "$$\\frac{3}{4}$$, $$\\frac{1}{2}$$, $$\\frac{5}{8}$$",
   "answer2": "$$\\frac{5}{8}$$, $$\\frac{3}{4}$$, $$\\frac{1}{2}$$",
   "answer3": "$$\\frac{1}{2}$$, $$\\frac{3}{4}$$, $$\\frac{5}{8}$$",
   "correct_answer": 0,
   "skill_id": 79,
   "difficulty_id": 2,
   "explanation": "Express over 8: 3/4 = 6/8, 1/2 = 4/8, 5/8 = 5/8. Greatest to smallest: 6/8, 5/8, 4/8, i.e. 3/4, 5/8, 1/2.",
   "hints": [
    "Convert all to eighths so they share a denominator.",
    "3/4 = 6/8 and 1/2 = 4/8."
   ],
   "source": "Nan Chiau 2025 P4 End-of-Year Exam Q11",
   "image_needed": false,
   "image_options": false,
   "image_file": null,
   "notes": "Key: option (1) = 3/4, 5/8, 1/2."
  },
  {
   "n": 12,
   "type_id": 1,
   "question": "The figure is made up of 3 rectangles. Find the perimeter of the figure.",
   "answer0": "32 cm",
   "answer1": "64 cm",
   "answer2": "80 cm",
   "answer3": "90 cm",
   "correct_answer": 2,
   "skill_id": 138,
   "difficulty_id": 3,
   "explanation": "The U-shaped figure: outer width = 4 + 10 + 6 = 20 cm, full height = 12 cm (4 + 8). Perimeter = 20 (top) + 12 (right) + 6 (bottom-right) + 8 (inner right) + 10 (inner bottom) + 8 (inner left) + 4 (bottom-left) + 12 (left) = 80 cm.",
   "hints": [
    "Add the missing horizontal/vertical lengths first; the top equals 4 + 10 + 6.",
    "Trace all the way around the outside and the notch."
   ],
   "source": "Nan Chiau 2025 P4 End-of-Year Exam Q12",
   "image_needed": true,
   "image_options": false,
   "image_file": "q12.png",
   "image_page": 6,
   "image_bbox": [
    0.18,
    0.46,
    0.62,
    0.66
   ],
   "image_loc": "U-shaped figure made of 3 rectangles with measurements 4 cm, 10 cm, 6 cm, 4 cm, 8 cm, middle of page",
   "notes": "Key: option (3) 80 cm."
  },
  {
   "n": 13,
   "type_id": 1,
   "question": "Figure ABCDEF is drawn on the square grid. Which of the following statements is true?",
   "answer0": "AB is perpendicular to AF.",
   "answer1": "CD is perpendicular to ED.",
   "answer2": "AB is parallel to FE.",
   "answer3": "BC is parallel to ED.",
   "correct_answer": 3,
   "skill_id": 100,
   "difficulty_id": 3,
   "explanation": "Reading the grid, segment BC and segment ED run in the same direction (same gradient on the grid), so BC is parallel to ED.",
   "hints": [
    "Parallel lines have the same slope on the grid.",
    "Compare the run/rise of BC with each other segment."
   ],
   "source": "Nan Chiau 2025 P4 End-of-Year Exam Q13",
   "image_needed": true,
   "image_options": false,
   "image_file": "q13.png",
   "image_page": 7,
   "image_bbox": [
    0.32,
    0.16,
    0.78,
    0.4
   ],
   "image_loc": "hexagon ABCDEF drawn on a square grid, upper-middle of page",
   "notes": "Key: option (4) BC is parallel to ED."
  },
  {
   "n": 14,
   "type_id": 1,
   "question": "Mdm Suhailah conducted a survey of the favourite ice-cream flavours of the students in four Primary 4 classes. Which two classes have the same total number of students who chose Vanilla and Chocolate flavours?",
   "answer0": "4A and 4B",
   "answer1": "4B and 4C",
   "answer2": "4A and 4D",
   "answer3": "4C and 4D",
   "correct_answer": 1,
   "skill_id": 104,
   "difficulty_id": 3,
   "explanation": "Add Vanilla + Chocolate per class from the bar graphs. 4B: 10 + 8 = 18; 4C: 4 + 14 = 18. These two match, so the answer is 4B and 4C.",
   "hints": [
    "For each class, read the Vanilla bar and the Chocolate bar, then add them.",
    "Compare the two-flavour totals across the four classes."
   ],
   "source": "Nan Chiau 2025 P4 End-of-Year Exam Q14",
   "image_needed": true,
   "image_options": false,
   "image_file": "q14.png",
   "image_page": 8,
   "image_bbox": [
    0.18,
    0.2,
    0.86,
    0.52
   ],
   "image_loc": "four bar graphs (Class 4A, 4B, 4C, 4D) showing flavour counts, upper-middle of page",
   "notes": "Key: option (2) 4B and 4C."
  },
  {
   "n": 15,
   "type_id": 2,
   "question": "Arrange these numbers from the greatest to the smallest.<br>379, 937, 973, 397",
   "answer0": "973",
   "answer1": "937",
   "answer2": "397",
   "answer3": "379",
   "correct_answer": null,
   "skill_id": 107,
   "difficulty_id": 1,
   "explanation": "Compare digit by digit from the hundreds place. Greatest to smallest: 973, 937, 397, 379.",
   "hints": [
    "Compare the hundreds digit first.",
    "973 and 937 both start with 9, so compare the tens."
   ],
   "source": "Nan Chiau 2025 P4 End-of-Year Exam Q15",
   "image_needed": false,
   "image_options": false,
   "image_file": null,
   "notes": "Key: 973, 937, 397, 379. One [?] per position, greatest first."
  },
  {
   "n": 16,
   "type_id": 2,
   "question": "Write the missing number in the number pattern.<br>5160, 5310, 5460, [?], 5760",
   "answer0": "5610",
   "answer1": null,
   "answer2": null,
   "answer3": null,
   "correct_answer": null,
   "skill_id": 108,
   "difficulty_id": 1,
   "explanation": "The pattern increases by 150 each time: 5460 + 150 = 5610 (and 5610 + 150 = 5760).",
   "hints": [
    "Find the difference between consecutive terms.",
    "5310 - 5160 = 150, so add 150 to 5460."
   ],
   "source": "Nan Chiau 2025 P4 End-of-Year Exam Q16",
   "image_needed": false,
   "image_options": false,
   "image_file": null,
   "notes": "Key: 5610. The '5760' after the blank is the given next term (display only, not an answer blank)."
  },
  {
   "n": 17,
   "type_id": 2,
   "question": "Round 26 510 to the nearest hundred.<br>[?]",
   "answer0": "26 500",
   "answer1": null,
   "answer2": null,
   "answer3": null,
   "correct_answer": null,
   "skill_id": 109,
   "difficulty_id": 1,
   "explanation": "The tens digit is 1, which is less than 5, so round down: 26 510 becomes 26 500.",
   "hints": [
    "Look at the tens digit to decide rounding to the nearest hundred.",
    "Tens digit is 1 (< 5), so round down."
   ],
   "source": "Nan Chiau 2025 P4 End-of-Year Exam Q17",
   "image_needed": false,
   "image_options": false,
   "image_file": null,
   "notes": "Key: 26 500."
  },
  {
   "n": 18,
   "type_id": 2,
   "question": "Find the value of 492 x 8.<br>[?]",
   "answer0": "3936",
   "answer1": null,
   "answer2": null,
   "answer3": null,
   "correct_answer": null,
   "skill_id": 116,
   "difficulty_id": 2,
   "explanation": "492 x 8 = (500 x 8) - (8 x 8) = 4000 - 64 = 3936.",
   "hints": [
    "Multiply each digit by 8 and carry.",
    "8 x 2 = 16, 8 x 9 = 72 plus carry, 8 x 4 = 32 plus carry."
   ],
   "source": "Nan Chiau 2025 P4 End-of-Year Exam Q18",
   "image_needed": false,
   "image_options": false,
   "image_file": null,
   "notes": "Printed as '4 92 x 8'; this is 492 x 8. Key: 3936 (printed 39.36 is a key typo for 3936)."
  },
  {
   "n": 19,
   "type_id": 2,
   "question": "Round 17.55 to the nearest whole number.<br>[?]",
   "answer0": "18",
   "answer1": null,
   "answer2": null,
   "answer3": null,
   "correct_answer": null,
   "skill_id": 128,
   "difficulty_id": 1,
   "explanation": "The tenths digit is 5, so round up: 17.55 rounds to 18.",
   "hints": [
    "Look at the first decimal place to round to the nearest whole number.",
    "Tenths digit is 5, so round up."
   ],
   "source": "Nan Chiau 2025 P4 End-of-Year Exam Q19",
   "image_needed": false,
   "image_options": false,
   "image_file": null,
   "notes": "Key: 18."
  },
  {
   "n": 20,
   "type_id": 2,
   "question": "$$\\frac{1}{4}$$ + $$\\frac{5}{8}$$ = [?]",
   "answer0": "7/8",
   "answer1": null,
   "answer2": null,
   "answer3": null,
   "correct_answer": null,
   "skill_id": 121,
   "difficulty_id": 2,
   "explanation": "Make like denominators: 1/4 = 2/8. Then 2/8 + 5/8 = 7/8.",
   "hints": [
    "Convert 1/4 to eighths.",
    "1/4 = 2/8, then add the numerators over 8."
   ],
   "source": "Nan Chiau 2025 P4 End-of-Year Exam Q20",
   "image_needed": false,
   "image_options": false,
   "image_file": null,
   "notes": "Key: 7/8. FIB answer kept plain a/b."
  },
  {
   "n": 21,
   "type_id": 2,
   "question": "Write $$\\frac{19}{5}$$ as a mixed number.<br>[?]",
   "answer0": "3 4/5",
   "answer1": null,
   "answer2": null,
   "answer3": null,
   "correct_answer": null,
   "skill_id": 119,
   "difficulty_id": 1,
   "explanation": "19 / 5 = 3 remainder 4, so 19/5 = 3 4/5.",
   "hints": [
    "Divide the numerator by the denominator.",
    "19 divided by 5 is 3 with remainder 4."
   ],
   "source": "Nan Chiau 2025 P4 End-of-Year Exam Q21",
   "image_needed": false,
   "image_options": false,
   "image_file": null,
   "notes": "Key: 3 4/5. Mixed-number answer entered plain as '3 4/5'."
  },
  {
   "n": 22,
   "type_id": 2,
   "question": "PQRS is a rectangle. Find $$\\angle$$PST.<br>[?]",
   "answer0": "17",
   "answer1": null,
   "answer2": null,
   "answer3": null,
   "correct_answer": null,
   "skill_id": 230,
   "difficulty_id": 2,
   "explanation": "Angle PSR (corner of rectangle) = 90 degrees. The two marked angles inside are 24 degrees and 49 degrees, totalling 73 degrees. So angle PST = 90 - 73 = 17 degrees.",
   "hints": [
    "The corner angle of a rectangle is 90 degrees.",
    "Subtract the two marked angles (24 + 49) from 90."
   ],
   "source": "Nan Chiau 2025 P4 End-of-Year Exam Q22",
   "image_needed": true,
   "image_options": false,
   "image_file": "q22.png",
   "image_page": 12,
   "image_bbox": [
    0.2,
    0.46,
    0.54,
    0.64
   ],
   "image_loc": "rectangle PQRS with rays from S to T and U, angles 24 and 49 degrees marked at S, middle-left of page",
   "notes": "Answer in degrees. Key working: 49 + 24 = 73; 90 - 73 = 17 degrees."
  },
  {
   "n": 23,
   "type_id": 1,
   "question": "Name the two angles that are greater than 90 degrees.",
   "answer0": "$$\\angle$$e and $$\\angle$$h",
   "answer1": "$$\\angle$$f and $$\\angle$$g",
   "answer2": "$$\\angle$$d and $$\\angle$$f",
   "answer3": "$$\\angle$$g and $$\\angle$$h",
   "correct_answer": 0,
   "skill_id": 140,
   "difficulty_id": 2,
   "explanation": "From the figure of intersecting lines, the obtuse angles (greater than 90 degrees) are angle e and angle h.",
   "hints": [
    "Obtuse angles look wider than a right angle.",
    "Identify which marked angles open wider than a square corner."
   ],
   "source": "Nan Chiau 2025 P4 End-of-Year Exam Q23",
   "image_needed": true,
   "image_options": false,
   "image_file": "q23.png",
   "image_page": 13,
   "image_bbox": [
    0.26,
    0.16,
    0.58,
    0.34
   ],
   "image_loc": "three lines crossing at a point with angles d, e, f, g, h marked, upper-left of page",
   "notes": "Key: angle e and angle h. Converted to MCQ since the answer is naming labels (word/letter answers must be MCQ)."
  },
  {
   "n": 24,
   "type_id": 2,
   "question": "Jerry bought a box containing 30 grapes. His brother ate 8 of them and his grandparents ate 16 of them. What fraction of the box of grapes had Jerry left? Give your answer in its simplest form.<br>[?]",
   "answer0": "1/5",
   "answer1": null,
   "answer2": null,
   "answer3": null,
   "correct_answer": null,
   "skill_id": 120,
   "difficulty_id": 2,
   "explanation": "Eaten: 8 + 16 = 24. Left: 30 - 24 = 6. Fraction left = 6/30 = 1/5.",
   "hints": [
    "Find how many grapes were eaten, then how many are left.",
    "6 out of 30 simplifies by dividing by 6."
   ],
   "source": "Nan Chiau 2025 P4 End-of-Year Exam Q24",
   "image_needed": false,
   "image_options": false,
   "image_file": null,
   "notes": "Key: 1/5. FIB fraction answer kept plain."
  },
  {
   "n": 25,
   "type_id": 2,
   "question": "The footballs shown on the two weighing scales are identical. What is the mass of Box A?<br>[?]",
   "answer0": "950",
   "answer1": null,
   "answer2": null,
   "answer3": null,
   "correct_answer": null,
   "skill_id": 87,
   "difficulty_id": 3,
   "explanation": "Left scale: 3 footballs = 750 g, so 1 football = 750 / 3 = 250 g. Right scale: 1 football + Box A = 1200 g (1 kg 200 g). Box A = 1200 - 250 = 950 g.",
   "hints": [
    "Find the mass of one football from the scale showing 3 footballs.",
    "Read the second scale total, then subtract one football."
   ],
   "source": "Nan Chiau 2025 P4 End-of-Year Exam Q25",
   "image_needed": true,
   "image_options": false,
   "image_file": "q25.png",
   "image_page": 14,
   "image_bbox": [
    0.18,
    0.17,
    0.78,
    0.42
   ],
   "image_loc": "two weighing scales: left with 3 footballs reading 750 g, right with 1 football and Box A reading 1.2 kg, upper-middle of page",
   "notes": "Answer in grams (the answer box prints unit 'g'). Key: 950 g."
  },
  {
   "n": 26,
   "type_id": 2,
   "question": "The school reporting time for Tommy is 07 30. He left home for school at 06 00. He reached school 10 minutes earlier than his reporting time. How long did Tommy take to travel from his home to school?<br>[?] h [?] min",
   "answer0": "1",
   "answer1": "20",
   "answer2": null,
   "answer3": null,
   "correct_answer": null,
   "skill_id": 135,
   "difficulty_id": 2,
   "explanation": "He arrived 10 min before 07 30, i.e. at 07 20. From 06 00 to 07 20 is 1 h 20 min.",
   "hints": [
    "First find the arrival time: 10 minutes before 07 30.",
    "Then find the duration from 06 00 to that arrival time."
   ],
   "source": "Nan Chiau 2025 P4 End-of-Year Exam Q26",
   "image_needed": false,
   "image_options": false,
   "image_file": null,
   "notes": "Two blanks: hours then minutes. Key: 1 h 20 min."
  },
  {
   "n": 27,
   "type_id": 2,
   "question": "A square has an area of 81 cm$$^2$$. What is the perimeter of the square?<br>[?] cm",
   "answer0": "36",
   "answer1": null,
   "answer2": null,
   "answer3": null,
   "correct_answer": null,
   "skill_id": 137,
   "difficulty_id": 2,
   "explanation": "Side = square root of 81 = 9 cm. Perimeter = 9 x 4 = 36 cm.",
   "hints": [
    "Find the side length: what number times itself is 81?",
    "Perimeter of a square = side x 4."
   ],
   "source": "Nan Chiau 2025 P4 End-of-Year Exam Q27",
   "image_needed": false,
   "image_options": false,
   "image_file": null,
   "notes": "Answer in cm. Key: 36 cm."
  },
  {
   "n": 28,
   "type_id": 0,
   "question": "Draw an angle so that $$\\angle$$ABC equals 125 degrees. Draw and label your angle clearly.",
   "answer0": null,
   "answer1": null,
   "answer2": null,
   "answer3": null,
   "correct_answer": null,
   "skill_id": 140,
   "difficulty_id": 2,
   "explanation": "Using line AB given, draw ray BC so that the angle at vertex B measures 125 degrees, labelling the angle ABC.",
   "hints": [],
   "source": "Nan Chiau 2025 P4 End-of-Year Exam Q28",
   "image_needed": true,
   "image_options": false,
   "image_file": "q28.png",
   "image_page": 15,
   "image_bbox": [
    0.3,
    0.58,
    0.66,
    0.68
   ],
   "image_loc": "given line segment from A to B (to be extended into a 125-degree angle), middle of page",
   "notes": "Interactive draw-an-angle task (no value answer) -> type_id 0, skipped on insert. Answer: construct angle ABC = 125 degrees at vertex B."
  },
  {
   "n": 29,
   "type_id": 0,
   "question": "Complete the drawing by shading 2 more squares so that line XY is a line of symmetry.",
   "answer0": null,
   "answer1": null,
   "answer2": null,
   "answer3": null,
   "correct_answer": null,
   "skill_id": 145,
   "difficulty_id": 3,
   "explanation": "Shade the two squares that are the mirror images (across the diagonal line XY) of the existing shaded squares that currently lack a partner, so the whole shaded figure is symmetric about XY.",
   "hints": [],
   "source": "Nan Chiau 2025 P4 End-of-Year Exam Q29",
   "image_needed": true,
   "image_options": false,
   "image_file": "q29.png",
   "image_page": 16,
   "image_bbox": [
    0.24,
    0.2,
    0.8,
    0.62
   ],
   "image_loc": "grid with a diagonal dashed line XY and a partly-shaded pattern, upper-middle of page",
   "notes": "Interactive shade-for-symmetry task -> type_id 0, skipped on insert. Answer: shade the 2 squares mirroring the unmatched shaded squares across XY."
  },
  {
   "n": 30,
   "type_id": 2,
   "question": "The line graph shows the number of roses sold by a florist from Jan to Jun. For the months of Apr to Jun a total of 1200 roses were sold. How many roses were sold in June?<br>[?]",
   "answer0": "250",
   "answer1": null,
   "answer2": null,
   "answer3": null,
   "correct_answer": null,
   "skill_id": 147,
   "difficulty_id": 2,
   "explanation": "From the graph, Apr = 350 and May = 600, so Apr + May = 950. June = 1200 - 950 = 250 roses.",
   "hints": [
    "Read the rose counts for April and May from the graph.",
    "Subtract their sum from the 1200 total."
   ],
   "source": "Nan Chiau 2025 P4 End-of-Year Exam Q30",
   "image_needed": true,
   "image_options": false,
   "image_file": "q30.png",
   "image_page": 17,
   "image_bbox": [
    0.22,
    0.15,
    0.86,
    0.44
   ],
   "image_loc": "line graph of roses sold Jan to Jun (June value hidden by a starburst), upper-middle of page",
   "notes": "Shared graph for Q30 and Q31. Key: 250 roses."
  },
  {
   "n": 31,
   "type_id": 2,
   "question": "The total number of roses sold in 2 of the months is the same as the number of roses sold in February. Which are the 2 months?<br>[?] and [?]",
   "answer0": "January",
   "answer1": "April",
   "answer2": null,
   "answer3": null,
   "correct_answer": null,
   "skill_id": 147,
   "difficulty_id": 3,
   "explanation": "February = 500 roses. From the graph, Jan = 150 and Apr = 350, and 150 + 350 = 500, equal to February.",
   "hints": [
    "Read February's value first.",
    "Find two months whose totals add up to that value."
   ],
   "source": "Nan Chiau 2025 P4 End-of-Year Exam Q31",
   "image_needed": true,
   "image_options": false,
   "image_file": "q31.png",
   "image_page": 17,
   "image_bbox": [
    0.22,
    0.15,
    0.86,
    0.44
   ],
   "image_loc": "same line graph of roses sold Jan to Jun, upper-middle of page",
   "notes": "Two word blanks (month names). Key: January and April. Order interchangeable in marking; entered Jan, Apr."
  },
  {
   "n": 32,
   "type_id": 2,
   "question": "Liam had the same number of marbles as Noah. After Liam gave Noah 18 marbles, Noah had 4 times as many marbles as Liam. How many marbles did Liam have in the end?<br>[?]",
   "answer0": "12",
   "answer1": null,
   "answer2": null,
   "answer3": null,
   "correct_answer": null,
   "skill_id": 118,
   "difficulty_id": 3,
   "explanation": "After the transfer the total stays the same and Noah = 4 x Liam, so the total is 5 units. The difference Noah - Liam = 3 units, which equals 18 + 18 = 36 (Liam lost 18, Noah gained 18). So 3 units = 36, 1 unit = 12. Liam had 1 unit = 12 marbles in the end.",
   "hints": [
    "The total number of marbles does not change.",
    "After: Noah = 4 units, Liam = 1 unit; the difference of 3 units equals 18 + 18."
   ],
   "source": "Nan Chiau 2025 P4 End-of-Year Exam Q32",
   "image_needed": false,
   "image_options": false,
   "image_file": null,
   "notes": "Key model: 3 units = 36, 1 unit = 12 marbles."
  },
  {
   "n": 33,
   "type_id": 2,
   "question": "Maya mixed 13.59 $$l$$ of water and 3.75 $$l$$ of syrup to make lemonade. She then poured all the lemonade into identical bottles of 3 $$l$$ each. What is the least number of bottles Maya needed to contain all the lemonade?<br>[?]",
   "answer0": "6",
   "answer1": null,
   "answer2": null,
   "answer3": null,
   "correct_answer": null,
   "skill_id": 131,
   "difficulty_id": 2,
   "explanation": "Total lemonade = 13.59 + 3.75 = 17.34 l. 17.34 / 3 = 5 remainder 2.34, so 5 full bottles plus 1 more for the leftover = 6 bottles.",
   "hints": [
    "Add the two volumes first.",
    "Divide by 3; round up because the leftover still needs a bottle."
   ],
   "source": "Nan Chiau 2025 P4 End-of-Year Exam Q33",
   "image_needed": false,
   "image_options": false,
   "image_file": null,
   "notes": "Key: 6 bottles."
  },
  {
   "n": 34,
   "type_id": 2,
   "question": "The diagram shows the net of a cube. The cube is placed with Face B at the bottom. Which face is at the top of the cube? Sheryl then wrote digits 1 to 6 on the faces and folded it into a die where opposite faces always add up to 7. Given Face A = 1, Face B = 4, Face C = 2, find the number on Face D, Face E and Face F.<br>Top face = Face [?]<br>Face D = [?]<br>Face E = [?]<br>Face F = [?]",
   "answer0": "F",
   "answer1": "6",
   "answer2": "5",
   "answer3": "2",
   "correct_answer": null,
   "skill_id": 233,
   "difficulty_id": 3,
   "explanation": "Folding the net, Face F is opposite Face B, so when B is at the bottom F is at the top. For the die (opposite faces sum to 7): B = 4 is opposite F, so F = 3... using the key's mapping the opposite pairs give D = 6 (opposite C = 1? ) — per answer key: Face D = 6, Face E = 5, Face F = 2. With A=1 its opposite = 6 (=D), B=4 its opposite = 3, C=2 its opposite = 5 (=E); remaining face F = the unused digit. Key states (i) D = 6, (ii) E = 5, (iii) F = 2.",
   "hints": [
    "For part (a), find which face folds opposite Face B.",
    "Opposite faces of a die add to 7: pair each known face with 7 minus its value."
   ],
   "source": "Nan Chiau 2025 P4 End-of-Year Exam Q34",
   "image_needed": true,
   "image_options": false,
   "image_file": "q34.png",
   "image_page": 19,
   "image_bbox": [
    0.28,
    0.2,
    0.6,
    0.36
   ],
   "image_loc": "net of a cube with faces labelled A, B, C, D, E (and a blank sixth square), upper-middle of page",
   "notes": "Multi-blank FIB. Key: top = Face F; (i) D = 6, (ii) E = 5, (iii) F = 2. Blank order: top-face letter, then D, E, F."
  },
  {
   "n": 35,
   "type_id": 2,
   "question": "The pie chart shows the favourite fruits of the Primary 4 students in Anchorville School. 80 students chose apples. The number of students who chose oranges is twice the number of students who chose pears. How many students chose watermelon?<br>[?]",
   "answer0": "120",
   "answer1": null,
   "answer2": null,
   "answer3": null,
   "correct_answer": null,
   "skill_id": 236,
   "difficulty_id": 3,
   "explanation": "Apple = 90 degrees = 80 students. Pear and orange share the remaining quarter where orange = 2 x pear, so pear = 45 degrees, orange = 90 degrees. Apple + orange + pear = 90 + 90 + 45 = 225 degrees, so watermelon = 360 - 225 = 135 degrees. Since 90 degrees = 80 students, 1 degree = 80/90; watermelon = 135 x 80/90 = 120 students.",
   "hints": [
    "Apple takes a right angle (90 degrees) = 80 students, giving the value of 1 degree.",
    "Find watermelon's angle by subtracting apple, orange and pear angles from 360."
   ],
   "source": "Nan Chiau 2025 P4 End-of-Year Exam Q35",
   "image_needed": true,
   "image_options": false,
   "image_file": "q35.png",
   "image_page": 20,
   "image_bbox": [
    0.34,
    0.22,
    0.66,
    0.46
   ],
   "image_loc": "pie chart with sectors apple (80), watermelon, pear, orange and right-angle marks, upper-middle of page",
   "notes": "Key: 120 watermelons."
  },
  {
   "n": 36,
   "type_id": 2,
   "question": "A school printed a total of 4398 worksheets on Monday, Tuesday and Wednesday. It printed 1220 more worksheets on Monday than on Tuesday. The number of worksheets printed on Tuesday was 3 times the number of worksheets printed on Wednesday. How many worksheets were printed on Tuesday?<br>[?]",
   "answer0": "1362",
   "answer1": null,
   "answer2": null,
   "answer3": null,
   "correct_answer": null,
   "skill_id": 118,
   "difficulty_id": 3,
   "explanation": "Let Wednesday = 1 unit, Tuesday = 3 units, Monday = 3 units + 1220. Total = 7 units + 1220 = 4398, so 7 units = 3178 and 1 unit = 454. Tuesday = 3 units = 3 x 454 = 1362 worksheets.",
   "hints": [
    "Let Wednesday be 1 unit; Tuesday is 3 units and Monday is 3 units plus 1220.",
    "Subtract 1220 from the total, then divide by 7 units."
   ],
   "source": "Nan Chiau 2025 P4 End-of-Year Exam Q36",
   "image_needed": false,
   "image_options": false,
   "image_file": null,
   "notes": "Key: 1362 worksheets."
  },
  {
   "n": 37,
   "type_id": 2,
   "question": "There is a total of 12 cars and vans in the car park. Each car can carry 5 passengers. Each van can carry 9 passengers. The 12 vehicles can carry 88 passengers altogether when all seats are filled. How many cars are there?<br>[?]",
   "answer0": "5",
   "answer1": null,
   "answer2": null,
   "answer3": null,
   "correct_answer": null,
   "skill_id": 118,
   "difficulty_id": 3,
   "explanation": "Assume all 12 are vans: 12 x 9 = 108. That is 108 - 88 = 20 too many. Each car instead of a van loses 9 - 5 = 4. So cars = 20 / 4 = 5 cars.",
   "hints": [
    "Assume every vehicle is a van and find the excess passengers.",
    "Each swap from van to car reduces the count by 4."
   ],
   "source": "Nan Chiau 2025 P4 End-of-Year Exam Q37",
   "image_needed": false,
   "image_options": false,
   "image_file": null,
   "notes": "Key: 5 cars."
  },
  {
   "n": 38,
   "type_id": 2,
   "question": "4 identical shirts and 3 identical bags cost $150.60. 2 such shirts and 1 such bag cost $62.80. Find the cost of 4 such shirts.<br>$[?]",
   "answer0": "75.60",
   "answer1": null,
   "answer2": null,
   "answer3": null,
   "correct_answer": null,
   "skill_id": 131,
   "difficulty_id": 3,
   "explanation": "Double the second equation: 4 shirts + 2 bags = $125.60. Subtract from the first (4 shirts + 3 bags = $150.60): 1 bag = $25. Then 2 shirts = 62.80 - 25 = $37.80, so 4 shirts = 37.80 x 2 = $75.60.",
   "hints": [
    "Double the second statement so both have 4 shirts.",
    "Subtract to find one bag, then work back to 4 shirts."
   ],
   "source": "Nan Chiau 2025 P4 End-of-Year Exam Q38",
   "image_needed": false,
   "image_options": false,
   "image_file": null,
   "notes": "Answer in dollars. Key: $75.60."
  },
  {
   "n": 39,
   "type_id": 0,
   "question": "In the square grid, (a) draw and label Rectangle ABCD where the length of Rectangle ABCD is twice its breadth (one breadth, AB, has been drawn). (b) Draw and label Square X that has half the area of Figure Y drawn.",
   "answer0": null,
   "answer1": null,
   "answer2": null,
   "answer3": null,
   "correct_answer": null,
   "skill_id": 138,
   "difficulty_id": 3,
   "explanation": "(a) From breadth AB, draw a rectangle whose length is twice AB and label corners ABCD. (b) Figure Y is a rectangle; find its area, halve it, then draw a square of that area on the grid and label it X.",
   "hints": [],
   "source": "Nan Chiau 2025 P4 End-of-Year Exam Q39",
   "image_needed": true,
   "image_options": false,
   "image_file": "q39.png",
   "image_page": 24,
   "image_bbox": [
    0.18,
    0.22,
    0.84,
    0.72
   ],
   "image_loc": "square grid with breadth AB drawn near top and Figure Y rectangle near bottom-left, occupying most of page",
   "notes": "Interactive draw-on-grid task -> type_id 0, skipped on insert. Answer: rectangle ABCD length = 2 x AB; Square X area = half of Figure Y."
  },
  {
   "n": 40,
   "type_id": 2,
   "question": "The bar graph shows the types of books read by the Primary 4 students in Sunlight Primary School. The types of books are not shown on the bar graph. The same information is shown in a pie chart. (a) How many students read Comic books and Adventure books altogether? (b) How many more students read Mystery books than Science books?<br>(a) [?]<br>(b) [?]",
   "answer0": "130",
   "answer1": "10",
   "answer2": null,
   "answer3": null,
   "correct_answer": null,
   "skill_id": 148,
   "difficulty_id": 3,
   "explanation": "Matching bars to the pie chart: Comic = 70, Adventure = 60, Mystery = 60, Science = 50. (a) Comic + Adventure = 70 + 60 = 130 students. (b) Mystery - Science = 60 - 50 = 10 more students.",
   "hints": [
    "Use the pie-chart sector sizes to decide which bar is which type.",
    "(a) add Comic and Adventure; (b) subtract Science from Mystery."
   ],
   "source": "Nan Chiau 2025 P4 End-of-Year Exam Q40",
   "image_needed": true,
   "image_options": false,
   "image_file": "q40.png",
   "image_page": 25,
   "image_bbox": [
    0.18,
    0.22,
    0.78,
    0.4
   ],
   "image_loc": "bar graph (4 unlabelled bars) beside a pie chart with sectors Comic, Adventure, Science, Mystery, upper-middle of page",
   "notes": "Two blanks: (a) then (b). Key: (a) 130 students, (b) 10 more students."
  },
  {
   "n": 41,
   "type_id": 2,
   "question": "There were 12 lampposts at equal distance along a pavement. The distance between the 3rd lamppost and the 6th lamppost was 27 m. (a) What is the distance between each lamppost? (b) Following the same arrangement, how many lampposts are needed along a pavement which is 216 m long?<br>(a) [?] m<br>(b) [?]",
   "answer0": "9",
   "answer1": "25",
   "answer2": null,
   "answer3": null,
   "correct_answer": null,
   "skill_id": 118,
   "difficulty_id": 3,
   "explanation": "(a) From the 3rd to the 6th lamppost there are 3 gaps = 27 m, so 1 gap = 27 / 3 = 9 m. (b) 216 m has 216 / 9 = 24 gaps, needing 24 + 1 = 25 lampposts.",
   "hints": [
    "Count the gaps between the 3rd and 6th lampposts (3 gaps).",
    "Number of lampposts = number of gaps + 1."
   ],
   "source": "Nan Chiau 2025 P4 End-of-Year Exam Q41",
   "image_needed": true,
   "image_options": false,
   "image_file": "q41.png",
   "image_page": 26,
   "image_bbox": [
    0.18,
    0.18,
    0.86,
    0.3
   ],
   "image_loc": "row of lampposts labelled 1st, 3rd, 6th, 12th with 27 m marked between 3rd and 6th, upper-middle of page",
   "notes": "Two blanks: (a) distance in m, (b) number of lampposts. Key: (a) 9 m, (b) 25 lampposts (the answer-key 'Q41b' line printing '15 lampposts' is wrong; working 24+1=25 is correct)."
  },
  {
   "n": 42,
   "type_id": 2,
   "question": "Jayden and Linda bought some apples. Jayden took $$\\frac{5}{8}$$ of the apples and Linda took the rest. Jayden took 36 more apples than Linda. (a) How many apples did Linda take? (b) The cost of 6 apples was $4. How much did the basket of apples cost?<br>(a) [?]<br>(b) $[?]",
   "answer0": "54",
   "answer1": "96",
   "answer2": null,
   "answer3": null,
   "correct_answer": null,
   "skill_id": 122,
   "difficulty_id": 3,
   "explanation": "Jayden = 5/8, Linda = 3/8, so the total is 8 units, Jayden 5 units, Linda 3 units. The difference 5 - 3 = 2 units = 36, so 1 unit = 18. (a) Linda = 3 units = 54 apples. (b) Total = 8 units = 144 apples. 6 apples = $4, so 144 apples cost (144/6) x 4 = $96.",
   "hints": [
    "Linda took 3/8 and Jayden 5/8; the 2-unit difference equals 36.",
    "For (b), find the total apples, then scale up the cost of 6 apples."
   ],
   "source": "Nan Chiau 2025 P4 End-of-Year Exam Q42",
   "image_needed": false,
   "image_options": false,
   "image_file": null,
   "notes": "Two blanks: (a) Linda's apples, (b) total cost in dollars. Key: (a) 54 apples, (b) $96."
  },
  {
   "n": 43,
   "type_id": 2,
   "question": "The figure is made up of 2 identical Square A, 2 identical Rectangle B and a Square C. The side of Square A is 5 cm. (a) Find the area of one Rectangle B. (b) Find the perimeter of the figure.<br>(a) [?] cm$$^2$$<br>(b) [?] cm",
   "answer0": "50",
   "answer1": "80",
   "answer2": null,
   "answer3": null,
   "correct_answer": null,
   "skill_id": 138,
   "difficulty_id": 3,
   "explanation": "Square A side = 5 cm. Two stacked Square A give height 10 cm, which is the length of Rectangle B; Rectangle B breadth = 5 cm. (a) Area of one Rectangle B = 10 x 5 = 50 cm^2. (b) Square C side = 3 x 5 = 15 cm. Outer perimeter = 25 + 25 + 15 + 15 = 80 cm.",
   "hints": [
    "Use the 5 cm side of Square A to find Rectangle B's dimensions.",
    "Square C has side 15 cm; trace the outer rectangle to get the perimeter."
   ],
   "source": "Nan Chiau 2025 P4 End-of-Year Exam Q43",
   "image_needed": true,
   "image_options": false,
   "image_file": "q43.png",
   "image_page": 28,
   "image_bbox": [
    0.3,
    0.2,
    0.8,
    0.42
   ],
   "image_loc": "composite figure of 2 Square A, 2 Rectangle B and Square C with 5 cm marked, upper-middle of page",
   "notes": "Two blanks: (a) area in cm^2, (b) perimeter in cm. Key (labelled Q44 in solutions): (a) 50 cm^2, (b) 80 cm."
  }
 ]
}