Problem:
At the grocery store last week, small boxes of facial tissue were priced at boxes for . This week they are on sale at boxes for . The percent decrease in the price per box during the sale was closest to
Answer Choices:
A.
B.
C.
D.
E.
Solution:
Last week one box cost ; this week one box costs . The decrease, , compared to the original price of , is a decrease of or , so choice is closest.
Last week there was a -box offer and this week a -box offer. Consider a purchase of boxes (the smallest number divisible by both and . Last week boxes would have been offers). This week it is offers). The savings, , compared to is .
Answer: .
The problems on this page are the property of the MAA's American Mathematics Competitions