[{"id": 1, "type": "short_answer", "skill": "area", "question": "Find the area of a rectangle: length=8, width=7", "difficulty": "medium", "explanation": "A=l×w=8×7=56 sq units.", "needs_review": false, "correct_answer": "56"}, {"id": 2, "type": "multiple_choice", "skill": "perimeter", "options": ["56", "32", "15", "30"], "question": "Find the perimeter of a rectangle: length=8, width=7", "difficulty": "medium", "explanation": "P=2(l+w)=2(8+7)=2(15)=30", "needs_review": false, "correct_answer": "30"}, {"id": 3, "type": "short_answer", "skill": "computation", "question": "Calculate: 18 × 19", "difficulty": "medium", "explanation": "Multiply: 18×19=342", "needs_review": false, "correct_answer": "342"}, {"id": 4, "type": "short_answer", "skill": "computation", "question": "Calculate: 7 × 5", "difficulty": "medium", "explanation": "Multiply: 7×5=35", "needs_review": false, "correct_answer": "35"}, {"id": 5, "type": "short_answer", "skill": "computation", "question": "Calculate: 11 × 8", "difficulty": "medium", "explanation": "Multiply: 11×8=88", "needs_review": false, "correct_answer": "88"}, {"id": 6, "type": "short_answer", "skill": "computation", "question": "Calculate: 4 × 19", "difficulty": "medium", "explanation": "Multiply: 4×19=76", "needs_review": false, "correct_answer": "76"}, {"id": 7, "type": "short_answer", "skill": "computation", "question": "Calculate: 17 × 4", "difficulty": "medium", "explanation": "Multiply: 17×4=68", "needs_review": false, "correct_answer": "68"}, {"id": 8, "type": "short_answer", "skill": "computation", "question": "Calculate: 7 × 9", "difficulty": "medium", "explanation": "Multiply: 7×9=63", "needs_review": false, "correct_answer": "63"}]