A local farmer just outside of town grew watermelons for a living, and he was doing quite well but was being hassled by some local kids who would sneak into his watermelon patch late at night and eat his watermelons. After some careful thought, he came up with a clever idea that he thought would scare the kids away for sure.
He made a big sign and posted it right in the middle of the watermelon field. The next day the kids show up to eat and found the a sign that read, “Warning! One of the watermelons in this field has been injected with cyanide.”
Feeling violated, the kids made up their own sign and posted it next to the farmer’s sign, then ran off. When the farmer returned, he surveyed the field. He noticed that no watermelons are missing, but the sign next to his read, “Now there are two!”