BRAIN TEASER: Someone is asked to count from ten to one backward without screwing up. Most people can’t do it correctly the first time.

Wager with a friend to count from ten to one backward without making a mistake. Explain that you do not mean for him to do an about face and count the numbers out. Tell him that if he screws up, then you get to keep the money on the table or vice versa. Pretend to hypnotize him and say, “Go ahead and try it.”

Being careful, he will count in a loud clear voice, “10, 9, 8, 7, 6, 5, 4, 3, 2, 1.” Thinking he has succeeded, he will relax and smile.

The Secret: Pick up the money and put it in your pocket, saying, “Sorry, you screwed up.” Confused and indignant, he will say, “What?” Explain to your misguided pal that correctly counting from ten to one, backwards, would be 1, 2, 3, 4, 5, 6, 7, 8, 9, 10. Tricked, he will not be able to deny your explanation.