Riddle:
On a fine sunny day a ship was in the harbor. All of a sudden the ship began to sink. There was no storm and nothing wrong with the ship yet it sank right in front of the spectators eyes.
What caused the ship to sink?
Riddle: An electric train is going twenty miles/hour up a hillside of a forty-five degrees upward. The wind is blowing downhill at a speed of thirty miles/hour. What way will the steam from the train go?
Answer: There is no steam, it's an electric train!