A programmer and an engineer are sitting next to each other on a long flight. The programmer leans over to the engineer and asks if he would like to play a fun game.
The engineer just wants 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 and he explains, "I ask you a question. If you don't know the answer, you pay me $5. Then, you ask me a question. If I don't know the answer, I'll pay you $5."
Again, the engineer politely declines and tries to get to sleep. The programmer, by 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'll pay you $50!"
This catches the engineer's 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, but reaches into his wallet, pulls out a $5 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, puzzled. He takes out his laptop computer and searches all of his references. He taps into the airphone with his modem and searches the net and the Library of Congress.
Frustrated, he sends email to all of his coworkers -- all to no avail.
After about an hour, he wakes the engineer and hands him $50.
The engineer politely takes the $50 and turns away, to try to get back to sleep.
The programmer, more than a little miffed, shakes the engineer and asks, "Well, so what's the answer?"
Without a word, the engineer reaches into his wallet, hands the programmer $5 and turns away, to get back to sleep!