What goes up a hill with three legs, and comes down with four?

A lawyer and a blonde are sitting next to each other on a long flight.

The lawyer thinks blondes are dumb and that he can get one over on her easily, so the lawyer asks if the blonde would like to play a fun game.

The blonde is tired and just wants to take a nap, so she politely declines and tries to fall asleep.

The lawyer persists saying that the game is a lot of fun. "I'll ask you a question, and if you don't know the answer, you pay me only $5, then you'll ask me one, and if I don't know the answer, I'll pay you $500."

This catches the blonde's attention and to keep the lawyer quiet, she agrees to play the game.

The lawyer asks the first question. "What's the distance from the Earth to the Moon?"

The blonde quietly reaches into her pocket, pulls out a five-dollar bill, and hands it to the lawyer.

Now it's the blonde's turn. She asks, "What goes up a hill with three legs, and comes down with four?"

The lawyer uses his laptop and searches all the references he could find on the internet; he sends e-mails to all the smart friends he knows, all to no avail. After an hour of searching, he finally gives up.

He wakes up the blonde and hands her $500. The blonde pockets the $500 and goes right back to sleep.

The lawyer is going nuts not knowing the answer. He wakes the blonde up and asks, "Well, so what goes up a hill with three legs and comes down with four?"

The blonde reaches into her pocket, hands the lawyer $5 and goes back to sleep.