Instead of studying for the last exam of their college careers, four seniors spent the night partying in the house they had rented off campus. The next morning they waited until the test would be almost finished before they made their way to class.

Along the way they each put grease on their hands to support the story they were going to tell their professor. The exam was almost over when the four seniors arrived at class. As planned, they told the professor that they had a flat tire along the way, and could they please retake the test?  The professor said he was a reasonable man, so he scheduled a test date for the following week. Their plan had worked!>

They studied diligently for the next week, making the most of their time. The day of the make up came and they were ready for anything.  Each was placed alone in a separate classroom for the test. The first> question, worth five points, was easy. The second question was worth  95 points.>

It read simply, "Which tire?"