A student reported for the University final examination which consists of "yes/no" type questions.
The student takes a seat in the examination hall, stares at the question paper for five minutes, and then in a fit of inspiration takes out a coin, starts flipping it and marking the answer sheet - Yes for Heads and No for Tails. Using this inspired technique, within half an hour the student is all done whereas the rest of the class is sweating it out.
During the last few minutes, the student is seen desperately throwing the coin, swearing and sweating.
The moderator, alarmed, approaches the student and asks what's going on.
"I finished the exam in half an hour," the student replies, "But, I'm rechecking my answers!!"