Two fraternity buddies at Duke University were so confident about their chemistry final Monday that they went the University of Virginia and partied all weekend, intending to study all day Sunday. Instead, they were in bed with hangovers and did not get back until early Monday morning. Rather than take the final unprepared, they told their professor, Jerard, that they had a flat tire and couldn't make it back in time, and he agreed to let them take the exam the next day. They studied that night and went to Jerard's office at the agreed time. Jerard put them in separate rooms, gave them each a slim test booklet, and told them to begin. The first problem, worth five points, was something simple about elements. "Cool," they thought, "this is going to be easy," and turned the page. The problem on the next page, worth 95 points, said simply: "Which tire?"