My math teacher told me this one today Two guys were flying over the Sahara Desert in a hot air balloon. They were completely lost, and had no way to find out where to go to get to civilization. Suddenly, they see a man walking on the ground. Thinking they may be close to some kind of settlement, one guy calls down to the man: ""HEY! WHERE ARE WE?!"" The two in the balloon wait what seems like forever, until finally the man calls back: ""IN THE DESERT!"" and the man was then lost from their sight. ""What an idiot,"" said one man. ""He's not an idiot,"" said the second man, ""He's just a mathematician."" ""A mathematician? How could you know that?"" ""Three reasons. One, it takes forever for the answer. Second, he's 100% correct, and third, the information he provided was completely useless.""