[{"id": 1, "type": "short_answer", "skill": "area", "question": "Find the area of a rectangle: length=10, width=8", "difficulty": "medium", "explanation": "A=l×w=10×8=80 sq units.", "needs_review": false, "correct_answer": "80"}, {"id": 2, "type": "multiple_choice", "skill": "perimeter", "options": ["80", "40", "18", "36"], "question": "Find the perimeter of a rectangle: length=10, width=8", "difficulty": "medium", "explanation": "P=2(l+w)=2(10+8)=2(18)=36", "needs_review": false, "correct_answer": "36"}, {"id": 3, "type": "short_answer", "skill": "computation", "question": "Calculate: 2 × 14", "difficulty": "medium", "explanation": "Multiply: 2×14=28", "needs_review": false, "correct_answer": "28"}, {"id": 4, "type": "short_answer", "skill": "computation", "question": "Calculate: 19 × 16", "difficulty": "medium", "explanation": "Multiply: 19×16=304", "needs_review": false, "correct_answer": "304"}, {"id": 5, "type": "short_answer", "skill": "computation", "question": "Calculate: 14 × 16", "difficulty": "medium", "explanation": "Multiply: 14×16=224", "needs_review": false, "correct_answer": "224"}]