Flummoxed by his true-false final exam, a student decides to toss a coin up in the air. Heads means true; tails, false. Thirty minutes later, he’s done, well before the rest of the class. But then the student starts flipping the coin again. And soon he’s swearing and sweating over each question.
"What’s wrong?" asks the concerned teacher.
"I’m rechecking my answers," says says the student.