Riddle: Place three piles of matches on a table, one with 11 matches, the second with 7, and the third with 6. You are to move matches so that each pile holds 8 matches. You may add to any pile only as many matches as it already contains. All the matches must come from one other pile. For example, if a pile holds 6 matches, you may add 6 to it, no more or less.
You have three moves. How can you do it?
Answer: First pile to second; second to third; third to first:
| Pile | Initial number | First move | Second move | Third move |
| First | 11 | 11-7=4 | 4 | 4+4=8 |
| Second | 7 | 7+7=14 | 14-6=8 | 8 |
| Third | 6 | 6 | 6+6=12 | 12-4=8 |
