A local bookstore has a sale on all their paperbacks giving a 10% discount. You also received a coupon in the mail for $4 off your purchase. If you buy 2 paperbacks at $8 each, is it less expensive for you to apply the discount before the coupon or after the coupon?

Discount before the Coupon

Step-by-step explanation:

The cost of two paperbacks at $8 each=2 X $8 = $16

First, we determine for the case in which the coupon is applied first.

If the $4 Coupon is applied,

Cost=$16-$4 = $12

If the 10% discount is further applied,

Amount to be paid = $12 - (10% of $12) = $12-1.2 = $10.8

However if the discount is applied first,

Book Cost=$16 - (10% of $16) = 16-1.6=14.4

If the Coupon is then applied,

Amount to be paid = $ (14.4-4) = $10.4

Since $10.4 is less than $10.8, we conclude therefore that it is less expensive to apply the discount first.