Riddle: You have two coins, and their total value is 11¢. One of the coins is not a penny. What are the two coins?
Answer: The two coins are a dime and a penny. I said "ONE of the coins is not a penny"; if one of the coins is not a penny, then the other coin IS a penny. The coin that is not a penny has to be a dime because the total value should be 11¢.