Question Everything

Bored during a long flight, Professor Charles Hall, an eminent physicist leaned over and woke up Chaim Yankel who was sitting next to him, sleeping.

“Would you like to play a game?” asked the Professor.

"I'll ask you a question," the Professor explained, "and if you don't know the answer, you pay me $5. Then you ask me a question, and if I don't know the answer, I'll pay you $50."

“OK,” said Chaim Yankel calmly.

"What's the distance from the earth to the moon?" Confused, Chaim Yankel him $5. "Ha!" said the Professor. "It's 238,857 miles. Now it's your turn."

Chaim Yankel was silent for a few moments. Then he asked, "What goes up a hill with three legs and comes down with four?"

Puzzled, the Professor racked his brains for an hour--but to no avail. Finally he took out his wallet and handed over $50. "Okay, okay, what is the answer?" the Professor asked.

Chaim Yankel said, "I don't know," pulled out a $5 bill, handed it to the Professor, and went back to sleep.