Two guys were taking chemistry at the University of Louisville. They did pretty well on all of the quizzes, midterms, and labs, and had a solid "A" going into the final. They were so confident that the weekend before finals (the chemistry final was on Monday), they decided to go up to the University of Kentucky and party with some friends.

They had a great time, however, they overslept on Sunday and didn't make it back to Louisville until early Monday morning. Rather than take the final then, they found their professor after the final and explained to him why they missed it.

They told him that they went up to the University of Kentucky for the weekend, and had planned to come back in time to study, but they had a flat tire on the way back. They didn't have a spare, and couldn't get help for a long time and that's why they were late in getting back to campus. The professor thought this over and told them they could make up the final the following day.

The two guys were elated and relieved. They studied that night and went in the next day to take the final. The professor placed them in separate rooms, handed each of them a test booklet, and told them to begin. They each looked at the first problem, which was worth 5 Points. It was a simple question about molarity and solutions. "Cool," they thought. "This is going to be easy." They answered the question and then turned the page.They were not prepared, however, for what they saw on this page. It said: (95 Points)—Which tire?