Question: One day there was a man in a hospital bed, and there was a man sitting next to him. So, the doctor asked the man sitting next to the man in the hospital bed, he asked, who are you? The man said listen closely for I will only tell you this once. Brothers and sisters I have none, but this man's father is my father's son. Who is this man?
Answer: His son!
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.