Knife and Cup Puzzle
You will need:
3 Acme Knives
4 Acme Cups, all the same size
Place 3 of the cups in a triangle formation, upside down on the tabletop. The distance between each must be the length of an Acme Knife. See the diagram below.
Suspend the 4th cup in the middle of the other
3 using only 3 knives and 3 cups.
The 4th cup cannot touch the table.
The knives cannot touch the table.
The cups in the triangle cannot be moved.