[{"id": 1, "type": "short_answer", "skill": "area", "question": "Find the area of a rectangle: length=5, width=7", "difficulty": "medium", "explanation": "A=l×w=5×7=35 sq units.", "needs_review": false, "correct_answer": "35"}, {"id": 2, "type": "multiple_choice", "skill": "perimeter", "options": ["20", "12", "24", "35"], "question": "Find the perimeter of a rectangle: length=5, width=7", "difficulty": "medium", "explanation": "P=2(l+w)=2(5+7)=2(12)=24", "needs_review": false, "correct_answer": "24"}, {"id": 3, "type": "short_answer", "skill": "computation", "question": "Calculate: 14 × 3", "difficulty": "medium", "explanation": "Multiply: 14×3=42", "needs_review": false, "correct_answer": "42"}, {"id": 4, "type": "short_answer", "skill": "computation", "question": "Calculate: 18 × 7", "difficulty": "medium", "explanation": "Multiply: 18×7=126", "needs_review": false, "correct_answer": "126"}, {"id": 5, "type": "short_answer", "skill": "computation", "question": "Calculate: 7 × 10", "difficulty": "medium", "explanation": "Multiply: 7×10=70", "needs_review": false, "correct_answer": "70"}]