[{"id": 1, "type": "short_answer", "skill": "area", "question": "Find the area of a rectangle: length=6, width=6", "difficulty": "medium", "explanation": "A=l×w=6×6=36 sq units.", "needs_review": false, "correct_answer": "36"}, {"id": 2, "type": "multiple_choice", "skill": "perimeter", "options": ["24", "12", "36", "24"], "question": "Find the perimeter of a rectangle: length=6, width=6", "difficulty": "medium", "explanation": "P=2(l+w)=2(6+6)=2(12)=24", "needs_review": false, "correct_answer": "24"}, {"id": 3, "type": "short_answer", "skill": "computation", "question": "Calculate: 3 × 4", "difficulty": "medium", "explanation": "Multiply: 3×4=12", "needs_review": false, "correct_answer": "12"}, {"id": 4, "type": "short_answer", "skill": "computation", "question": "Calculate: 2 × 3", "difficulty": "medium", "explanation": "Multiply: 2×3=6", "needs_review": false, "correct_answer": "6"}, {"id": 5, "type": "short_answer", "skill": "computation", "question": "Calculate: 18 × 6", "difficulty": "medium", "explanation": "Multiply: 18×6=108", "needs_review": false, "correct_answer": "108"}]