A university professor and a university student were sitting next to each other on a long flight. The university professor said to the student "If you can answer my one question I will give you one hundred dollars. And if I can answer your question, you will give me one hundred dollars."
The student agreed, and elected to be the question-giver. The student asked "What has three legs, takes 2 minutes to climb a pine tree thirty feet high, and 5 hours to get back down again?"
The university professor thought about this for the entire flight. Ten hours later the plane landed and the professor admitted defeat, paying the student one hundred dollars. The professor then asked for the answer. The student replied, "I don't know either."
