A man owned a casino and invited some friends. It was a dark, stormy night, and they all placed their money on the table right before the lights went out. When the lights came back on, the money was gone. The owner put a rooster in an old rusty tea kettle. He told everyone to get in line and touch the kettle after he turned the lights off, and the rooster will crow when the robber touched it. After everyone touched it, the rooster didn’t crow, so the man told everyone to hold out their hands. After examining all the hands, he pointed out who the robber was.
Because the tea kettle was rusty, whoever touched it would have rust on their hands. The robber didn’t touch the kettle, therefore he was the only one whose hands weren’t rusty.