The schoolteacher asked a boy this question: "Suppose your mother baked a pie and there were six of you -- your mother, your father and four children. What percentage of the pie would you get?"

"One-fifth," replied the boy.

The teacher responded, "I'm afraid you don't know your fractions. Remember, there are six of you."

"I know," said the boy, "but you don't know my mother. She would say she didn't want any pie so we could have more."