{
  "paper": {
    "school": "Raffles Girls' Primary School",
    "year": 2023,
    "level": "P2",
    "label": "Revision 4",
    "source_prefix": "Raffles Girls 2023 P2 Revision 4",
    "has_answer_key": true,
    "topic": "Mass"
  },
  "questions": [
    {
      "n": 1,
      "type_id": 1,
      "question": "The mass of an apple is [?] .",
      "answer0": "10g",
      "answer1": "10kg",
      "answer2": "100g",
      "answer3": "100kg",
      "correct_answer": 2,
      "skill_id": 52,
      "difficulty_id": 1,
      "explanation": "An apple is small and light, so a sensible everyday mass for one apple is about 100g. 10g is far too light, and the kilogram options are far too heavy.",
      "hints": ["A small object like an apple is measured in grams, not kilograms.", "About how heavy is one apple in your hand? Around 100g."],
      "source": "Raffles Girls 2023 P2 Revision 4 Q1",
      "image_needed": false,
      "image_options": false,
      "image_file": null,
      "notes": "Answer key: 3 (1-based) = 100g, which is answer2 (0-based index 2)."
    },
    {
      "n": 2,
      "type_id": 1,
      "question": "Arrange the following items accordingly. Begin with the lightest.",
      "answer0": "rice, sugar, flour",
      "answer1": "flour, sugar, rice",
      "answer2": "sugar, flour, rice",
      "answer3": "flour, rice, sugar",
      "correct_answer": 1,
      "skill_id": 53,
      "difficulty_id": 2,
      "explanation": "Read each scale. Flour is the lightest, then sugar, then rice is the heaviest, so ordered from lightest to heaviest it is flour, sugar, rice.",
      "hints": ["Read where the needle points on each scale to find each mass.", "Lightest goes first; compare the three readings."],
      "source": "Raffles Girls 2023 P2 Revision 4 Q2",
      "image_needed": true,
      "image_options": false,
      "image_file": "q2.png",
      "notes": "Options are item-label word lists, so MCQ per FIB rule. Figure: three weighing scales labelled RICE, FLOUR, SUGAR with needle readings, image_page 1, middle of page below the question. Answer key: 2 (1-based) = flour, sugar, rice = answer1 (0-based index 1)."
    },
    {
      "n": 3,
      "type_id": 2,
      "question": "Bob bought 350g of butter. His sister used 250g of the butter. How much butter did he have left? He had [?] g of butter left.",
      "answer0": "100",
      "answer1": null,
      "answer2": null,
      "answer3": null,
      "correct_answer": null,
      "skill_id": 54,
      "difficulty_id": 1,
      "explanation": "350g - 250g = 100g. He had 100g of butter left.",
      "hints": ["Subtract the mass used from the mass bought.", "350 - 250 = ?"],
      "source": "Raffles Girls 2023 P2 Revision 4 Q3",
      "image_needed": false,
      "image_options": false,
      "image_file": null,
      "notes": "Answer key: 350 - 250 = 100g."
    },
    {
      "n": 4,
      "type_id": 2,
      "question": "Miss Liu has 900g of clay. She gave 250g to James and some to Meiling. She is left with 475g of clay. How much clay was given to Meiling? She gave Meiling [?] g of clay.",
      "answer0": "175",
      "answer1": null,
      "answer2": null,
      "answer3": null,
      "correct_answer": null,
      "skill_id": 54,
      "difficulty_id": 2,
      "explanation": "After giving James 250g: 900 - 250 = 650g. She is left with 475g, so Meiling got 650 - 475 = 175g of clay.",
      "hints": ["First take away the clay given to James from the total.", "Then subtract what she has left to find Meiling's share."],
      "source": "Raffles Girls 2023 P2 Revision 4 Q4",
      "image_needed": false,
      "image_options": false,
      "image_file": null,
      "notes": "Answer key: 900 - 250 = 650; 650 - 475 = 175g."
    },
    {
      "n": 5,
      "type_id": 2,
      "question": "Alice bought 5 similar packets of rice. The mass of each packet is 5kg. What is the total mass of rice that she bought? She bought [?] kg of rice.",
      "answer0": "25",
      "answer1": null,
      "answer2": null,
      "answer3": null,
      "correct_answer": null,
      "skill_id": 54,
      "difficulty_id": 1,
      "explanation": "5 packets each of 5kg: 5 x 5 = 25kg of rice in total.",
      "hints": ["Multiply the number of packets by the mass of each packet.", "5 x 5 = ?"],
      "source": "Raffles Girls 2023 P2 Revision 4 Q5",
      "image_needed": false,
      "image_options": false,
      "image_file": null,
      "notes": "Answer key: 5 x 5 = 25kg."
    },
    {
      "n": 6,
      "type_id": 2,
      "question": "Mrs Lim has 18kg of meat. She packs them equally into 6 bags. What is the mass of each bag? Each bag has a mass of [?] kg.",
      "answer0": "3",
      "answer1": null,
      "answer2": null,
      "answer3": null,
      "correct_answer": null,
      "skill_id": 54,
      "difficulty_id": 1,
      "explanation": "Share 18kg equally into 6 bags: 18 / 6 = 3kg per bag.",
      "hints": ["Divide the total mass by the number of bags.", "18 / 6 = ?"],
      "source": "Raffles Girls 2023 P2 Revision 4 Q6",
      "image_needed": false,
      "image_options": false,
      "image_file": null,
      "notes": "Answer key: 18 / 6 = 3kg."
    }
  ]
}