Mark: The teacher gave me a tough one today. It's about money.
Tim: Hm. What's the problem?
Mark: All right. "Sam has $8. Billy has nothing."
Tim: Wait, wait, wait. Should use real money. Eight bucks?
Mark: Yeah.
Tim: Four, five, six... cool. All right, go ahead.
Mark: All right.
Tim: I'll be Sam. You be Billy.
Mark: Sam gives Billy, 50% of what he has.
Tim: That's $4. One, two, three, four.
Mark: Thanks, Sam.
Tim: All right. Now, Billy gives Sam, 50% of what he has.
Tim: That's two out of the four. OK.
Mark: One, two.
Tim: That's pretty simple. OK.
Mark: All right. Now, Sam gives Billy, a hundred percent of what he has left.
Tim: All right.
Mark: "...how much does Sam have?"
Tim: Nothing.
Mark: Exactly. Thanks, Sam. [walks away with the money]
Tim: Sam wasn't a real bright guy, was he?