A celebrated Harvard tale about exams begins with four young scholars who, following a semester of riotous living, retired to a lodge in Maine owned by one of their families for some intensive study. Amid the cold air and clean living they found that Reading Period was insufficient to fill the gap in their colletive knowledge. They purposely missed their first exam and used the extra time to prepare, then presented themselves to the professor one day later with an excuse they thought was airtight.
"Professor," their designated spokesman intoned, "we were on the way back from a remote part of Maine and had a flat tire. The spare was also flat, and in the time it took to get it fixed we were delayed a whole day."
The Learned One, who was wiser than those young pups could divine, accepted the excuse and said that they would be allowed to take a make-up exam. Our four heroes could scarcely contain their glee. "In fact," he went on, "I'll give it to you right now." This cooled their spirits a bit, but, after all, they were by now well-versed in the subject, so they agreed.
The professor wrote one question on four separate pieces of paper and then walked each member of the quartet to a vacant classroom. On opening the paper, each man found the killer question:
"Which tire was it?"