The blonde reported for her University final examination which
consists of "yes/no" type questions. She takes her seat in the
examination hall, stares at the question paper for five minutes, and
then in a fit of inspiration takes her purse out, removes a coin and
starts tossing the coin and marking the answer sheet - Yes for Heads
and No for Tails. Within half an hour she is all done whereas the
rest of the class is sweating it out.

During the last few minutes, she is seen desperately throwing the
coin, swearing and sweating.

The moderator, alarmed, approaches her and asks what is going on.

"I finished the exam in half an hour. But, she says, I am rechecking
my answers."