Hard to believe this is college level but here we go! You're finding what the price is of a book that is $39.99 at a 40% discount. In order to find the answer you multiply your price times the discount in decimal form. Then subtract this value from the original.
40% ⇒ .40 (Note: Percentages are out of 100)
[39.99 x .40] = <span>15.996
[39.99 - </span>15.996] = <span>23.994
</span><span>The bookstore pays $23.99 per copy. </span>
