Lucky Guess, Mister

Teacher: Jordan*! Can you tell us the answer to the problem on the board?
Student talking in back of class: Um… No, sir.
Teacher: You are interrupting the class! What were you talking about?
Student: Petroleum lightsabers.

http://www.overheardinminneapolis.com/2007/05/which_are_way_cooler_than_math.html