A boy read a restaurant sign that advertised fat-free French fries.
"Sounds great," said the health-conscious boy. He ordered some.
He watched as the cook pulled a basket of fries from the fryer. The potatoes were dripping with oil when the cook put them into the container.
"Wait a minute," the boy said. "Those don't look fat-free."
"Sure they are," the cook said. "We charge only for the potatoes. The fat is free!"