[{"id": 1, "type": "short_answer", "skill": "area", "question": "Find the area of a rectangle: length=11, width=4", "difficulty": "medium", "explanation": "A=l×w=11×4=44 sq units.", "needs_review": false, "correct_answer": "44"}, {"id": 2, "type": "multiple_choice", "skill": "perimeter", "options": ["15", "30", "44", "44"], "question": "Find the perimeter of a rectangle: length=11, width=4", "difficulty": "medium", "explanation": "P=2(l+w)=2(11+4)=2(15)=30", "needs_review": false, "correct_answer": "30"}, {"id": 3, "type": "short_answer", "skill": "computation", "question": "Calculate: 19 × 17", "difficulty": "medium", "explanation": "Multiply: 19×17=323", "needs_review": false, "correct_answer": "323"}, {"id": 4, "type": "short_answer", "skill": "computation", "question": "Calculate: 16 × 15", "difficulty": "medium", "explanation": "Multiply: 16×15=240", "needs_review": false, "correct_answer": "240"}, {"id": 5, "type": "short_answer", "skill": "computation", "question": "Calculate: 5 × 19", "difficulty": "medium", "explanation": "Multiply: 5×19=95", "needs_review": false, "correct_answer": "95"}]