At Duke University, there were two sophomores taking Organic Chemistry who did so well on all the quizzes, mid-terms and labs, etc, that going into the final they had a solid 'A'. These two friends were so confident going into the final that the weekend before finals, even though the Chem final was on Monday, they decided to go up to the University of Virginia and party with some friends up there.

However, with their hangovers and the hard partying, they overslept all day Sunday and didn't make it back to Duke until early Monday morning. Rather than taking the final then, they decided to find their Professor after the final and explain (lie) to him about why they missed the final. They told their Professor they went to UVA for the weekend and planned to come back in time to study. Unfortunately, they had a flat tire on the way back, didn't have a spare, and couldn't get help for a long time. As a result, they were late getting back to campus and didn't have any time to study.

The Professor thought it over and then agreed they could make up the final the following day. The two guys were elated and relieved. So they studied that night and went in the next day at the time the Professor had told them.

He placed them in separate rooms and handed each of them a test booklet and told them to begin. They looked at the first problem, which was something simple about free radical formation and was worth 5 points. "Cool," they thought, "this is going to be easy." They did that problem and then turned the page. They were unprepared, however, for what they saw on the next page.

It said:
(95 points) Which tire?