[{"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: 6 × 14", "difficulty": "medium", "explanation": "Multiply: 6×14=84", "needs_review": false, "correct_answer": "84"}, {"id": 4, "type": "short_answer", "skill": "computation", "question": "Calculate: 11 × 16", "difficulty": "medium", "explanation": "Multiply: 11×16=176", "needs_review": false, "correct_answer": "176"}, {"id": 5, "type": "short_answer", "skill": "computation", "question": "Calculate: 17 × 11", "difficulty": "medium", "explanation": "Multiply: 17×11=187", "needs_review": false, "correct_answer": "187"}, {"id": 6, "type": "short_answer", "skill": "computation", "question": "Calculate: 16 × 19", "difficulty": "medium", "explanation": "Multiply: 16×19=304", "needs_review": false, "correct_answer": "304"}, {"id": 7, "type": "short_answer", "skill": "computation", "question": "Calculate: 11 × 11", "difficulty": "medium", "explanation": "Multiply: 11×11=121", "needs_review": false, "correct_answer": "121"}, {"id": 8, "type": "short_answer", "skill": "computation", "question": "Calculate: 11 × 3", "difficulty": "medium", "explanation": "Multiply: 11×3=33", "needs_review": false, "correct_answer": "33"}]