Two guys were on a plane. One guy, Dr. Newman asked the other guy, Jeff, to play a game. "If I don't know the answer to a question you ask, I pay you five dollars. If I ask you a question you don't know, you pay me five dollars." Jeff considered this and decided it was too risky. Later, Dr. Newman asked to play the same game but if he gets a question wrong he pays Jeff $500, and if Jeff gets one wrong he only has to pay Dr. Newman $5. Jeff said he would, of course, and Dr. Newman asked Jeff a hard history question. Jeff didn't know the answer so he paid Dr. Newman $5. Jeff then asked Dr. Newman, "What goes up a hill on four…