I'd been working on my business degree for about a year when I finally got to take a popular finance course. I went to the bookstore to buy the text and was shocked to find out that it would cost me $96. I asked how much it was worth if I sold it back at the end of the semester.  

"You'll get $24," said the clerk.  

"This is insane," I protested as I wrote out the check.  

"I know," replied the clerk sympathetically. "I've always thought that a person who buys a book for $96 and then sells it back for $24 should fail the course."