{
  "paper": {
    "school": "Nan Hua",
    "year": 2025,
    "level": "P3",
    "label": "Weighted Assessment 3",
    "source_prefix": "Nan Hua 2025 P3 Weighted Assessment 3",
    "has_answer_key": true
  },
  "questions": [
    {
      "n": 1,
      "type_id": 1,
      "question": "Which of the following shows an acute angle?",
      "answer0": "Angle 1",
      "answer1": "Angle 2",
      "answer2": "Angle 3",
      "answer3": "Angle 4",
      "correct_answer": 0,
      "skill_id": 99,
      "difficulty_id": 1,
      "explanation": "An acute angle is smaller than a right angle (90 degrees). Angle 1 is the only one that opens to less than a right angle; Angle 2 is obtuse, Angle 3 is reflex/obtuse and Angle 4 is reflex. Answer: Angle 1.",
      "hints": ["An acute angle is smaller than a right angle (a square corner).", "Compare each angle to a 90-degree corner; pick the one clearly less than that."],
      "source": "Nan Hua 2025 P3 Weighted Assessment 3 Q1",
      "image_needed": true,
      "image_options": true,
      "image_file": null,
      "image_page": 2,
      "image_bbox": [0.28, 0.24, 0.78, 0.50],
      "image_loc": "Four labelled angle diagrams (Angle 1 to Angle 4) in two rows, middle of page",
      "notes": "Image-option MCQ: the four options are angle pictures (Angle 1-4). Crop each option to q1_opt0..q1_opt3.png. Key: Q1 = option 1 (Angle 1)."
    },
    {
      "n": 2,
      "type_id": 1,
      "question": "Which figure has five angles?",
      "answer0": "Figure 1",
      "answer1": "Figure 2",
      "answer2": "Figure 3",
      "answer3": "Figure 4",
      "correct_answer": 0,
      "skill_id": 98,
      "difficulty_id": 2,
      "explanation": "Count the corners (angles) of each shaded figure on the grid. Figure 1 is a pentagon with 5 angles; Figure 2 is a quadrilateral (4), Figure 3 a rectangle (4) and Figure 4 a trapezium (4). Answer: Figure 1.",
      "hints": ["The number of angles equals the number of corners of the shape.", "A five-sided figure (pentagon) has exactly five corners."],
      "source": "Nan Hua 2025 P3 Weighted Assessment 3 Q2",
      "image_needed": true,
      "image_options": false,
      "image_file": "q2.png",
      "image_page": 3,
      "image_bbox": [0.36, 0.18, 0.72, 0.40],
      "image_loc": "Grid containing four shaded figures labelled Figure 1 to Figure 4, upper-middle of page",
      "notes": "Key: Q2 = option 1 (Figure 1)."
    },
    {
      "n": 3,
      "type_id": 1,
      "question": "Which of the following fractions is not an equivalent fraction of 1/2?",
      "answer0": "6/12",
      "answer1": "2/10",
      "answer2": "3/6",
      "answer3": "4/8",
      "correct_answer": 1,
      "skill_id": 77,
      "difficulty_id": 2,
      "explanation": "Simplify each: 6/12 = 1/2, 2/10 = 1/5, 3/6 = 1/2, 4/8 = 1/2. Only 2/10 is not equal to 1/2. Answer: 2/10.",
      "hints": ["A fraction equals 1/2 when the numerator is exactly half the denominator.", "Check 2/10: half of 10 is 5, not 2, so it is not 1/2."],
      "source": "Nan Hua 2025 P3 Weighted Assessment 3 Q3",
      "image_needed": false,
      "image_options": false,
      "image_file": null,
      "notes": "Key: Q3 = option 2 (2/10)."
    },
    {
      "n": 4,
      "type_id": 1,
      "question": "In the number line, which of the following marks 7 3/4?",
      "answer0": "A",
      "answer1": "B",
      "answer2": "C",
      "answer3": "D",
      "correct_answer": 2,
      "skill_id": 69,
      "difficulty_id": 2,
      "explanation": "The number line from 7 to 8 is divided into 4 equal parts, each part = 1/4. 7 3/4 is the third mark after 7, which is C. Answer: C.",
      "hints": ["The gap from 7 to 8 is split into 4 equal parts, so each step is 1/4.", "Count three quarter-steps from 7: that lands on C."],
      "source": "Nan Hua 2025 P3 Weighted Assessment 3 Q4",
      "image_needed": true,
      "image_options": false,
      "image_file": "q4.png",
      "image_page": 4,
      "image_bbox": [0.20, 0.18, 0.85, 0.28],
      "image_loc": "Horizontal number line from 7 to 8 with marks A, B, C, D between them, top of page",
      "notes": "Key: Q4 = option 3 (C)."
    },
    {
      "n": 5,
      "type_id": 1,
      "question": "What fraction of the figure is shaded?",
      "answer0": "3/7",
      "answer1": "2/5",
      "answer2": "2/3",
      "answer3": "4/5",
      "correct_answer": 1,
      "skill_id": 42,
      "difficulty_id": 2,
      "explanation": "The strip is divided into 10 equal triangles. 4 of them are shaded, giving 4/10 = 2/5. Answer: 2/5.",
      "hints": ["Count the total number of equal triangles, then the shaded ones.", "Shaded over total = 4/10; simplify by dividing both by 2 to get 2/5."],
      "source": "Nan Hua 2025 P3 Weighted Assessment 3 Q5",
      "image_needed": true,
      "image_options": false,
      "image_file": "q5.png",
      "image_page": 4,
      "image_bbox": [0.38, 0.45, 0.72, 0.53],
      "image_loc": "Horizontal strip of alternating up/down triangles, some shaded, middle of page",
      "notes": "Key: Q5 = option 2 (2/5). Verify count: 10 triangles total, 4 shaded."
    },
    {
      "n": 6,
      "type_id": 1,
      "question": "Which of the following correctly describes the figure?",
      "answer0": "RQ is perpendicular to NM, and QP is parallel to NO",
      "answer1": "RL is perpendicular to LM, and QP is parallel to PO",
      "answer2": "RQ is perpendicular to PO, and PO is parallel to NO",
      "answer3": "PO is perpendicular to NO, and QP is parallel to NO",
      "correct_answer": 3,
      "skill_id": 100,
      "difficulty_id": 3,
      "explanation": "On the grid, QP and NO are both vertical line segments, so QP is parallel to NO. PO is horizontal and NO is vertical, so PO is perpendicular to NO. Both statements in option 4 are true. Answer: option 4.",
      "hints": ["Parallel lines run in the same direction and never meet; perpendicular lines meet at a right angle.", "QP and NO are both vertical (parallel); PO and NO meet at a right angle (perpendicular)."],
      "source": "Nan Hua 2025 P3 Weighted Assessment 3 Q6",
      "image_needed": true,
      "image_options": false,
      "image_file": "q6.png",
      "image_page": 5,
      "image_bbox": [0.30, 0.13, 0.72, 0.36],
      "image_loc": "Grid with a house-like figure: triangle apex L over points R, Q, N, M and verticals down to P, O",
      "notes": "Options are perpendicular/parallel statements using symbols. Key: Q6 = option 4."
    },
    {
      "n": 7,
      "type_id": 2,
      "question": "Arrange the following fractions from the greatest to the smallest. 2/9 , 2/11 , 1/3 [?] [?] [?]",
      "answer0": "1/3",
      "answer1": "2/9",
      "answer2": "2/11",
      "answer3": null,
      "correct_answer": null,
      "skill_id": 79,
      "difficulty_id": 2,
      "explanation": "Convert to compare: 1/3 = 0.333, 2/9 = 0.222, 2/11 = 0.182. For 2/9 and 2/11 the numerators are equal, so the larger denominator (11) gives the smaller fraction. Greatest to smallest: 1/3, 2/9, 2/11.",
      "hints": ["When numerators are the same, the fraction with the larger denominator is smaller.", "Compare 1/3 (about 0.33), 2/9 (about 0.22), 2/11 (about 0.18) to order them."],
      "source": "Nan Hua 2025 P3 Weighted Assessment 3 Q7",
      "image_needed": false,
      "image_options": false,
      "image_file": null,
      "notes": "Ordering task converted to FIB: three blanks greatest->smallest. Key: 1/3, 2/9, 2/11."
    },
    {
      "n": 8,
      "type_id": 0,
      "question": "Draw a line parallel to line AB that passes through Point C.",
      "answer0": null,
      "answer1": null,
      "answer2": null,
      "answer3": null,
      "correct_answer": null,
      "skill_id": 101,
      "difficulty_id": 2,
      "explanation": "Line AB rises at a slope on the grid (for every 3 squares across it goes 2 squares up). Through point C draw a line with the exact same slope (same across/up grid steps) so it never meets AB; that line is parallel to AB.",
      "hints": ["Parallel lines have the same slant and never cross.", "Count the grid steps of AB (across and up) and repeat the same steps starting at C."],
      "source": "Nan Hua 2025 P3 Weighted Assessment 3 Q8",
      "image_needed": true,
      "image_options": false,
      "image_file": "q8.png",
      "image_page": 6,
      "image_bbox": [0.24, 0.47, 0.78, 0.78],
      "image_loc": "Square grid with sloped line AB and point C above it",
      "notes": "Interactive draw-a-line task — no value answer, type_id 0 (skipped on insert). Answer key shows the parallel line drawn through C."
    },
    {
      "n": 9,
      "type_id": 2,
      "question": "3/4 - 3/8 = [?]\n1/2 + 1/10 = [?]",
      "answer0": "3/8",
      "answer1": "3/5",
      "answer2": null,
      "answer3": null,
      "correct_answer": null,
      "skill_id": 81,
      "difficulty_id": 2,
      "explanation": "(a) 3/4 - 3/8 = 6/8 - 3/8 = 3/8. (b) 1/2 + 1/10 = 5/10 + 1/10 = 6/10 = 3/5.",
      "hints": ["Make the denominators the same before adding or subtracting (use 8 for part a, 10 for part b).", "Simplify the final fraction to its simplest form."],
      "source": "Nan Hua 2025 P3 Weighted Assessment 3 Q9",
      "image_needed": false,
      "image_options": false,
      "image_file": null,
      "notes": "Two FIB blanks (parts a and b). Answer key prints (b) as 2/5, but 1/2 + 1/10 = 6/10 = 3/5; key is wrong, corrected to 3/5. (a) = 3/8 matches key."
    },
    {
      "n": 10,
      "type_id": 2,
      "question": "Sam walked 840 m from his house to the library. Then, he walked to the school. The distance between the library and the school is 220 m further than the distance between Sam's house and the library. How far did he walk from his house to the school? Give your answer in km and m. [?] km [?] m",
      "answer0": "1",
      "answer1": "900",
      "answer2": null,
      "answer3": null,
      "correct_answer": null,
      "skill_id": 87,
      "difficulty_id": 2,
      "explanation": "Library to school = 840 + 220 = 1060 m. Total walked = 840 + 1060 = 1900 m = 1 km 900 m.",
      "hints": ["First find the library-to-school distance: 840 + 220.", "Add both legs (house-to-library + library-to-school), then convert 1900 m to km and m."],
      "source": "Nan Hua 2025 P3 Weighted Assessment 3 Q10",
      "image_needed": false,
      "image_options": false,
      "image_file": null,
      "notes": "Two FIB blanks (km and m). Figure (house/library/school) is decorative only, not needed to solve. Key: 1 km 900 m."
    },
    {
      "n": 11,
      "type_id": 2,
      "question": "Annie placed a papaya and a 10 g weight on a weighing scale as shown in Figure 1.\n(a) What is the mass of the papaya? [?] g\n(b) Then, she placed the papaya and a watermelon on another weighing scale as shown in Figure 2. What is the mass of the watermelon? [?] g",
      "answer0": "740",
      "answer1": "2560",
      "answer2": null,
      "answer3": null,
      "correct_answer": null,
      "skill_id": 87,
      "difficulty_id": 3,
      "explanation": "(a) Figure 1 scale reads 750 g for papaya + 10 g weight, so papaya = 750 - 10 = 740 g. (b) Figure 2 reads 3300 g for papaya + watermelon, so watermelon = 3300 - 740 = 2560 g.",
      "hints": ["The first scale shows the combined mass of the papaya and the 10 g weight; subtract 10 g.", "The second scale shows papaya + watermelon together; subtract the papaya's mass."],
      "source": "Nan Hua 2025 P3 Weighted Assessment 3 Q11",
      "image_needed": true,
      "image_options": false,
      "image_file": "q11.png",
      "image_page": 9,
      "image_bbox": [0.20, 0.16, 0.72, 0.40],
      "image_loc": "Two weighing scales: Figure 1 (papaya + 10 g, grams dial reading 750) and Figure 2 (watermelon, kg dial reading about 3.3 kg)",
      "notes": "Two FIB blanks (parts a and b). Scale readings must be read from the dials: Fig 1 = 750 g, Fig 2 = 3300 g. Key: a) 740 g, b) 2560 g."
    }
  ]
}