A mathematician, a philosopher, and a blonde all go to Hell and receive a challenge from the Devil -- if they can stump him, they're free to go to heaven instead. The philosopher goes first and asks the Devil a very hard philosophy question -- to which the Devil snaps his fingers, gets a book, and gives the answer. The mathematician tries as well -- but the Devil instantly gets the answer. When it comes to the blonde, she pulls up a chair and drills three holes in it. She then sits down in the chair and farts.
"Now," she says, "which hole did the fart come out of?"