A professor was giving a big test one day to his students. He
handed out all the tests and went back to his desk to wait. Once
the test was over the students all handed the tests back in. The
professor noticed one of his students had attached a $100 bill
to his test with a note saying, “A dollar per point.” The next
class the professor handed the tests back out. The student got
back his test and the $64 change.