Gynecologist Mechanic:

A gynecologist was getting tired of his job and decided to switch careers. He'd always enjoyed tinkering with truck engines, so he enrolled in a school for truck mechanics. When the class ended the students were given their final exam: strip a truck engine completely and reassemble it in perfect working order.

The gynecologist did his best - and was amazed to find he scored 150%. "How could that be?" he asked.

"Well," said the instructor, "I gave you 50% for taking the engine apart. Next, I gave you 50% for reassembling it - a fantastic job, really. And then I gave you a 50% bonus for doing it all through the exhaust pipe."