The blond has had a rough week, drops into her first class seat on Friday afternoon. Guy sits down next to her, starts hitting on her. Not interested. Let's play a game, he says. We take turns asking each other questions. If you can't answer correctly, you pay $5. No thanks, she says. All right then, I'll pay you $500, you pay me $5 he repsonds. (How smart can a blond be, he thinks.)

She sighs and says OK. What goes up the hill on 3 legs and comes down on 4? He Googles, he calls his bright friends, checks Wikipedia, etc., etc. No luck.

I give up, he says and hands her $500. So, he asks, what goes up the hill on three legs and comes down on 4? She shrugs and hands him $5.