This question is just for fun, and should be community wiki, but I don't know how to set that here.
Just as on Jeopardy, give an answer as the clue. Bonus points if the answer is in the Jeopardy "style", and contains puns or hints to the intended question.
See, e.g. http://www.youtube.com/watch?v=iJT20WxfHss, or
http://www.youtube.com/watch?v=LR5X5mB5JmI&feature=related
Then, in the comments, people submit answers. It is hard to avoid answers with more than one question in a mathematical context, so bonus points to the most elegant questions.
First, I will give an example of a bad question and a more elegant one to a given answer, and second, I will give an example of an answer, and a better answer written more in line with the Jeopardy style.
Answer: 3.14.
Bad Question: What is 3 + .14?
Better Question: What are the first 3 digits of $\pi$?
Ok Answer: $\frac{21}{6}$
Better Answer: This well-known sum probably adds up to $\frac{21}{6}$
Question: What is the expected value of a die roll?
