another dumb blonde joke

A sleepy blonde is on an airplane. A lawyer takes the seat beside her and looks her over. He likes what he sees.

Lawyer says, "Cutie, I know a game that will pass the time. I ask you a question, and if you can't answer it you give me five dollars. Then you ask me a question, and if I can't answer I give you five dollars."

Blonde twirls her hair with her index finger and giggles. "I don't think so, honey." Then she closes her eyes.

Lawyer persists. "C'mon, don't be a chicken. Tell you what: if you can't answer my question you give me five dollars, but if I can't answer your question I'll give you fifty dollars."

Blonde says, "Oh, okay, that sounds good. You can ask first."

Lawyer: "How many miles is it from the earth to the moon?"

Blonde thinks a moment, then hands the lawyer five dollars.

Lawyer cackles. "Your turn. Betcha can't stump me!"

Blonde considers. Finally she says, "Try this one. What goes up a hill on three legs, and comes down on four legs?" She closes her eyes again.

The lawyer puzzles. He googles it. He emails his friends. He can't figure it out. It's killing him. Meanwhile, the blonde is snoozing peacefully beside him. As the plane lands three hours later, she wakes up. "Well?" she asks him. "Figure it out yet?" The lawyer reluctantly reaches for his wallet and peels fifty dollars off his wad. She giggles and slings her carry-on over her shoulder as the plane rolls up to the gate.

"Wait!" shouts the lawyer as she disembarks ahead of him. "You didn't tell me the answer! What the hell is it that goes up a hill on three legs and comes down on four legs?"

The blonde hands the lawyer back five dollars. And walks away.