|Make two copies of this puzzle.
Make the second copy the mirror image of the first. That gives you
twelve pieces rather than six. It gives
you twelve puzzles rather than one.
Five of the six pieces have mirror images which are different from themselves. When you substitute a mirror image for one of these five, you have a new puzzle. The new puzzle has a different solution. One of the twleve different puzzles has seven solutions: it's the easiest to solve.
One of the twleve has no solution.
THE DIABOLICAL TRUTH...
These puzzles are
rather difficult to solve, and when someone finds a solution to one it
can be rather difficult to remember that solution. Changing just
one piece in the puzzle might make it the impossible puzzle. A person
who has just discovered a solution will usually not realize when a substitute
is made (mirror images look pretty much alike). If the new puzzle
is the impossible puzzle, the solution has mysteriously disappeared.