[{"id": 1, "type": "short_answer", "skill": "area", "question": "Find the area of a rectangle: length=10, width=6", "difficulty": "medium", "explanation": "A=l×w=10×6=60 sq units.", "needs_review": false, "correct_answer": "60"}, {"id": 2, "type": "multiple_choice", "skill": "perimeter", "options": ["60", "16", "32", "40"], "question": "Find the perimeter of a rectangle: length=10, width=6", "difficulty": "medium", "explanation": "P=2(l+w)=2(10+6)=2(16)=32", "needs_review": false, "correct_answer": "32"}, {"id": 3, "type": "short_answer", "skill": "computation", "question": "Calculate: 6 × 9", "difficulty": "medium", "explanation": "Multiply: 6×9=54", "needs_review": false, "correct_answer": "54"}, {"id": 4, "type": "short_answer", "skill": "computation", "question": "Calculate: 19 × 18", "difficulty": "medium", "explanation": "Multiply: 19×18=342", "needs_review": false, "correct_answer": "342"}, {"id": 5, "type": "short_answer", "skill": "computation", "question": "Calculate: 14 × 12", "difficulty": "medium", "explanation": "Multiply: 14×12=168", "needs_review": false, "correct_answer": "168"}, {"id": 6, "type": "short_answer", "skill": "computation", "question": "Calculate: 11 × 3", "difficulty": "medium", "explanation": "Multiply: 11×3=33", "needs_review": false, "correct_answer": "33"}, {"id": 7, "type": "short_answer", "skill": "computation", "question": "Calculate: 4 × 3", "difficulty": "medium", "explanation": "Multiply: 4×3=12", "needs_review": false, "correct_answer": "12"}, {"id": 8, "type": "short_answer", "skill": "computation", "question": "Calculate: 3 × 6", "difficulty": "medium", "explanation": "Multiply: 3×6=18", "needs_review": false, "correct_answer": "18"}]