Start with 27 small cubes. Now put them together to make one larger cube. Without touching the sides of the larger cube, remove the cube in the middle to leave 26.

(Note: No one may touch the outer cubes or in any way do anything that would move or change them)

(In reply to re: the middle cube by SilverKnight)

The problem indeed does not say the middle top cube must remain in position. It does, however, state that we may not "in any way do anything that would move or change them."
Melting the ice cube causes the top middle cube to move, though you might say that the ice cube is really melting on its own. Thanks for explaining your comment.

Posted by Tristan on 2003-10-24 17:42:37