Problem:
A store normally sells windows at each. This week the store is offering one free window for each purchase of four. Dave needs seven windows and Doug needs eight windows. How many dollars will they save if they purchase the windows together rather than separately?
Answer Choices:
A.
B.
C.
D.
E.
Solution:
If Dave buys seven windows separately he will purchase six and receive one free, for a cost of . If Doug buys eight windows separately, he will purchase seven and receive one free, for a total cost of . The total cost to Dave and Doug purchasing separately will be . If they purchase fifteen windows together, they will need to purchase only windows, for a cost of , and will receive free. This will result in a savings of .
Answer: .
The problems on this page are the property of the MAA's American Mathematics Competitions