Answer:
How can you throw a ball 20 meters, and have it come back to you without hitting anything?
What is as big as you are and yet does not weigh anything?
How is it possible to always find what your looking for in the last place you look?
The yellow house has yellow window, the red house has red windows, what colour windows does the green house have?
I have two coins, one is marked George I and one is marked George IV. One is genuine but one is a forgery. Which is the forgery?
What is round, has a twin, and sees more than most?