| 序号 | 题目：3,7,9,11 | |
|---|---|---|
| 1 | ((11 + 9) − 3) + 7 | |
| 2 | ((11 − 3) + 7) + 9 | |
| 3 | ((9 + 7) − 3) + 11 | |
| 4 | ((9 + 7) + 11) − 3 | |
| 5 | ((11 + 7) − 3) + 9 | |
| 6 | ((11 + 7) + 9) − 3 | |
| 7 | ((11 + 9) + 7) − 3 | |
| 8 | (9 + (7 − 3)) + 11 | |
| 9 | (11 + (9 − 3)) + 7 | |
| 10 | (11 + 7) + (9 − 3) | |
| 11 | (7 + (9 − 3)) + 11 | |
| 12 | (11 + 9) + (7 − 3) | |
| 13 | (9 − 3) × (11 − 7) | |
| 14 | (9 + 7) + (11 − 3) | |
| 15 | (9 + (11 − 3)) + 7 | |
| 16 | (11 + (7 − 3)) + 9 | |