An economist is back in his old college town many years after
graduation and decides to drop in on one of his old professors.
He happens to see a copy of an exam sitting on the desk so he
picks it up to look at it. Upon deciding that it looks familiar he
comments to the professor that it is the same exam that he had
taken 10 years ago. The professor assures him that this is
correct but adds that this time the answers are different.