A programmer and an engineer are sitting next to each other on a long flight from LA to NY. The Programmer leans over to the Engineer and asks if he would like to play a fun game. The Engineer just want to take a nap, so he politely declines and rolls over to the window to catch a few winks.
The Programmer persists and explains that the game is really easy and a lot of fun. He explains "I ask you a question, and if you don't know the answer, you pay me $5." Again, the Engineer politely declines and tries to get some sleep.
The Programmer, now somewhat agitated, says "OK, if you don't know the answer you pay me $5, and if I don't know the answer, I will pay you $50!" This catches the Engineer's complete attention, and he sees no end to this torment unless he plays, so he agrees to the game.
The Programmer asks the first question. "What's the distance from the earth to the moon?" The Engineer doesn't say a word, reaches into his wallet, pulls out a five-dollar bill and hands it to the Programmer. Now, it's the Engineer's turn. He asks the Programmer: "What goes up a hill with three legs, and comes down with four?" The Programmer looks at him with a puzzled look, he takes out his laptop computer and searches all his references. He taps into the Airphone with his modem and searches the Net and the Library of Congress. Frustrated, he sends e-mails to all his co-workers and friends he knows. All to no avail.
After over an hour, he wakes the Engineer and hands him $50. The Engineer politely takes the $50 and turns away to get back to sleep. The Programmer, more than a little miffed, shakes the Engineer and asks, "Well, so what IS the answer?" Without a word, the Engineer reaches into his wallet, hands the Programmer $5 and goes back to sleep.