The author of a book on running receives a royalty of 75¢ per copy sold. If the royalty rate is 12% of the single copy price, how much money per copy does not go to the author?

Answer 1

0.12x = 0.75
x = $6.25

6.25 - 0.75 = ?

My, this is an old problem. Imagine buying a book for six bucks!