These four buddies have an exam on Monday but decide to go out and party Sunday night anyway. They wake up and skip class because of the bad hangovers they have from all of the drinking. They walk in Tuesday and apologize to the professor, saying their car got a flat tire, hoping he’ll let them take the exam anyway.
Prof: “you’ve all been good students in my class, so I will let you take the exam this afternoon after class.”
Ecstatic, the buddies go through the rest of their day, coming in after class to take the exam. The Professor seats them in four different rooms, each with a copy of the 2 page exam and a pencil. They all start, and the questions are very easy on the first page. They flip over the exam and the whole page is blank except for one question: “Which tire was it?”