A lawyer boarded a plane to go home for the weekend. He found his seat by a very tired lady who was trying to get some rest. When they were no more than ten minutes into the flight he asked her if she would play a game that he made up and was extremely eager to play. She said that she was too tired to play, but he continued asking and even started to explain the rules.
"To start off" he said, "I’ll ask you a question. If you get it right, you get five dollars, and if you get it wrong, I get five dollars. Then we'll switch turns"
But she again said she was just too tired. So he continued, this time with higher stakes,
"Ok fine, if you get a question wrong, you still only have to pay five dollars, but if I get one wrong, I have to pay five HUNDRED dollars."
So reluctantly she agreed, and he started his question,
"How far is it from the sun to the earth?"
Without much thought at all she pulled out her purse and gave him five dollars. Then she began her question,
"What goes up a hill with three red legs, and comes down with four green ones?"
With that he was completely stumped, so he called up his good friends, got out his laptop and started IM-ing everyone who was on, went to all the joke websites he knew, and kept this routine up for two hours. He then woke the lady up, who had gone to sleep while he was searching, and told her,
"I have absolutely no idea what the answer is, so...here's the five hundred dollars I owe you . . . . But just out of curiosity, what was the answer?"
Without a reply, she opened her purse and gave him five dollars