A student had been working on his business degree for about a year when he finally got to take a popular finance course. He went to the bookstore to buy the text and was shocked to find out that it would cost him $150. He asked how much it was worth if he sold it back at the end of the semester.
"You'll get $38," said the clerk.
"This is insane," he protested as he wrote out the check.
"I know," replied the clerk sympathetically. "I've always thought that a person who buys a book for $150 and then sells it back for $38 should fail the course."