A gynecologist wants a change of pace so she decides to become a mechanic. After two weeks' training, there's a test. Each student in the class is required to take apart an engine, and put it back together again.
When the results come back, another student sees the gyno's grade and complains,
"How did she get a 150% if 100% is a perfect score?"
"Well," the teacher says, "you got 50 points for taking the engine apart and 50 for putting it back together again."
"So, how did she get 150?"
"Well, she took it apart right, so there's 50, she put it back together right, another 50. But, she got an extra fifty for doing it all through the muffler."