Answer:
Six glasses are in a row. The first three are filled with milk and the last three are empty. By moving only one glass, can you arrange them so that the full and the empty glasses alternate?
An archaeologist unearths a coin bearing the inscription "57BC". How does he instantly know that it's a forgery?
What goes up and never comes down?
How could all of your cousins have an aunt who is not your aunt?
When is homework not homework?
A red house is made out of red bricks. A blue house is made out of blue bricks. What is a green house made out of?