Question: A hobo picks up cigarette butts from the ground and can make a cigarette with 4 butts. If he finds 16 cigarette butts, how many cigarettes can he make?
Answer: 5. He makes 4 cigarettes with the 16 butts. Then he smokes them and has 4 more butts to make another cigarette.
Question: A semi truck weighing exactly 10,000 pounds gets onto a bridge that is 100 miles long. The bridge's weight limit is exactly 10,000 pounds, any more will break the bridge. After going about 80 miles down the bridge a small bird lands on the truck.
Answer: Nothing, after traveling 80 miles the truck will have surely burnt enough fuel to allow the bird to land on the truck without breaking the bridge.