Jim stopped at a fast food restaurant, intrigued by a sign which offered fat-free fries. He decided to give them a try, but he was dismayed when the clerk pulled a batch of fries from the fryer dripping with fat, and then put a bag of these fries in with his order.

„Just a minute,” Jim said, „those aren’t fat-free.”

„Yes, they are,” the clerk replied, „we only charge for the potatoes, the fat is free.”