[{"id": 1, "type": "short_answer", "skill": "area", "question": "Find the area of a rectangle: length=8, width=6", "difficulty": "medium", "explanation": "A=l×w=8×6=48 sq units.", "needs_review": false, "correct_answer": "48"}, {"id": 2, "type": "multiple_choice", "skill": "perimeter", "options": ["14", "28", "48", "32"], "question": "Find the perimeter of a rectangle: length=8, width=6", "difficulty": "medium", "explanation": "P=2(l+w)=2(8+6)=2(14)=28", "needs_review": false, "correct_answer": "28"}, {"id": 3, "type": "short_answer", "skill": "computation", "question": "Calculate: 15 × 8", "difficulty": "medium", "explanation": "Multiply: 15×8=120", "needs_review": false, "correct_answer": "120"}, {"id": 4, "type": "short_answer", "skill": "computation", "question": "Calculate: 5 × 19", "difficulty": "medium", "explanation": "Multiply: 5×19=95", "needs_review": false, "correct_answer": "95"}, {"id": 5, "type": "short_answer", "skill": "computation", "question": "Calculate: 13 × 2", "difficulty": "medium", "explanation": "Multiply: 13×2=26", "needs_review": false, "correct_answer": "26"}]