At Penn State University , there were four sophomores taking chemistry
and all of them had an "A" so far. These four friends were so confident that,
the weekend before finals, they decided to visit some friends and have a big
party. They had a great time but, after all the hearty partying; they slept all
day Sunday and didn't make it back to Penn State until early Monday morning.

          Rather than taking the final then, they decided that after the final,
they would explain to their professor why they missed it. They said that they
visited friends but on the way back they had a flat tire.  As a result, they
missed the final. The professor agreed they could make up the final the next
day. The guys were excited and relieved.  They studied that night for the exam..

          The next day the professor placed them in separate rooms and gave
them a test booklet. They quickly answered the first problem worth 5 points.
Cool, they thought!  Each one in separate rooms, thinking this was going to be
easy. ...

          Then they turned the page. On the second page was written....

          For 95 points: Which tire? _________

H/T John Warden