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.
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