Kyra has a manufacturer's coupon for $5 off a box of diapers and a store coupon for 20% off any purchase. The store will let you use both coupons, but it does not have a policy about which coupon you must use first. What order should she use the coupons to get the maximum discount on a $40 box of diapers?
Logically, you should use the 20% off coupon first. This is because if you use it first, you will cut off the highest price with it. You will cut off $8, but if you use it second, you will only cut off $7.
You should use the store coupon first and the manufacturer's coupon second for the maximum discount. If you use this way, the box will cost $27