{
  "questions": [
    {
      "id": "q12_2_0",
      "question": "Sample question 1 for Volume of solids of revolution in Grade 12?",
      "options": {
        "A": "Option A for question 1",
        "B": "Option B for question 1",
        "C": "Option C for question 1",
        "D": "Option D for question 1"
      },
      "correct_answer": "A",
      "explanation": "This is explanation for question 1 about Volume of solids of revolution.",
      "hint": "Hint for question 1",
      "difficulty": "easy"
    },
    {
      "id": "q12_2_1",
      "question": "Sample question 2 for Volume of solids of revolution in Grade 12?",
      "options": {
        "A": "Option A for question 2",
        "B": "Option B for question 2",
        "C": "Option C for question 2",
        "D": "Option D for question 2"
      },
      "correct_answer": "B",
      "explanation": "This is explanation for question 2 about Volume of solids of revolution.",
      "hint": "Hint for question 2",
      "difficulty": "medium"
    },
    {
      "id": "q12_2_2",
      "question": "Sample question 3 for Volume of solids of revolution in Grade 12?",
      "options": {
        "A": "Option A for question 3",
        "B": "Option B for question 3",
        "C": "Option C for question 3",
        "D": "Option D for question 3"
      },
      "correct_answer": "C",
      "explanation": "This is explanation for question 3 about Volume of solids of revolution.",
      "hint": "Hint for question 3",
      "difficulty": "hard"
    }
  ]
}