A young man and an old man are sitting next to each other on a long flight. The flight has Wi-Fi and the young man decides to have a little fun with his travel companion.
The young man asks the old gentleman if he would like to play a game to pass the time. The old man responds that he is too tired and would just like to take a nap, but the young man presses and explains the rules of his game, “I’ll ask you any factual question and if you get it wrong, you pay me $1, then you ask me any factual question and if I get it wrong, I’ll pay you $100.” The old man raises an eyebrow and agrees to play.
“What is the distance from the earth to the moon?” asks the young man. The old man reaches into his pocket and gives the young man a dollar.
“What goes up a hill with three legs, but comes down with four?” asks the old man.
The young man smiles and opens up his laptop. After many Google searches, he finds nothing. He tries other search engines, still nothing. He searches Usenet archives, nothing. He begins instant messaging all his friends, still nothing. At the end of the flight, the old man wakes up and the young man hands him a $100 bill and says “OK, I give up! What goes up a hill with three legs, but comes down with four?”
The old man reaches into his pocket and hands the young man a dollar.