Four cars come to a four way stop, all coming from a different direction. They can't decide who got there first, so they all entered the intersection at the same time. They do not crash into each other. How is this possible?
Elmer Johnson went to the hardware store to make a purchase for his house.
He asked the store clerk, "How much will one cost?"
The clerk thought for a moment and said, "Three dollars."
Elmer Johnson, who looked a little puzzled said, "Well then, how much will twelve cost?"
"Six dollars," replied the clerk.
Elmer Johnson scratched his head and said, "If I were to purchase two hundred, how much would that cost?"
"That," said the clerk, "will cost you nine dollars." What was Elmer Johnson buying?