There was an exam in class one day. A blonde found that all of her questions were yes, no questions. So she took out a quarter and started flipping it, heads for yes, tails for no. After she had finnished the test she looked around and to her suprise she was the only one that was not sweating over the test. So she decided to check her booklet for errors. After a while she was getting very frustrated. So, the headmaster walked over and asked her what the problem was. She answered, "I finished my test within 30 minutes, but when I double-check them, they were all wrong."