[{"id": 1, "type": "short_answer", "skill": "area", "question": "Find the area of a rectangle: length=9, width=5", "difficulty": "medium", "explanation": "A=l×w=9×5=45 sq units.", "needs_review": false, "correct_answer": "45"}, {"id": 2, "type": "multiple_choice", "skill": "perimeter", "options": ["36", "45", "14", "28"], "question": "Find the perimeter of a rectangle: length=9, width=5", "difficulty": "medium", "explanation": "P=2(l+w)=2(9+5)=2(14)=28", "needs_review": false, "correct_answer": "28"}, {"id": 3, "type": "short_answer", "skill": "computation", "question": "Calculate: 14 × 14", "difficulty": "medium", "explanation": "Multiply: 14×14=196", "needs_review": false, "correct_answer": "196"}, {"id": 4, "type": "short_answer", "skill": "computation", "question": "Calculate: 2 × 13", "difficulty": "medium", "explanation": "Multiply: 2×13=26", "needs_review": false, "correct_answer": "26"}, {"id": 5, "type": "short_answer", "skill": "computation", "question": "Calculate: 20 × 17", "difficulty": "medium", "explanation": "Multiply: 20×17=340", "needs_review": false, "correct_answer": "340"}, {"id": 6, "type": "short_answer", "skill": "computation", "question": "Calculate: 3 × 20", "difficulty": "medium", "explanation": "Multiply: 3×20=60", "needs_review": false, "correct_answer": "60"}, {"id": 7, "type": "short_answer", "skill": "computation", "question": "Calculate: 17 × 5", "difficulty": "medium", "explanation": "Multiply: 17×5=85", "needs_review": false, "correct_answer": "85"}, {"id": 8, "type": "short_answer", "skill": "computation", "question": "Calculate: 2 × 17", "difficulty": "medium", "explanation": "Multiply: 2×17=34", "needs_review": false, "correct_answer": "34"}]