Question: This word problem appears in a teacher exam study guide. I, along with others, cannot get the answer that is provided in the answer key.

The problem: A builder is adding a 20' X 28' addition to a house. He has two choices: he can use 8" X 8" tile @ $.98 a tile or 12" X 12" tile @ $1.98 a tile. How much money would he save by using the least expensive choice?
The correct answer is $130. Could you please explain how they got this answer? A prompt response would greatly be appreciated!!!!

Hi Marguerite,

We don't get the answer in the answer key either.

The addition is 20' by 28' which is 240" by 336" so, with the smaller tiles (8" by 8") this is 30 tiles by 42 tiles or a total of 30 42 = 1260 tiles. At $0.98 per tile this would cost 1260 $0.98 = $1234.80. With the larger tiles (12" by 12") you need 20 28 = 560 tiles which cost $1.98 each and hence give a cost of 560 $1.98 = $1108.80. Thus the difference is $1234.80 - $1108.80 = $126.

Stephen and Penny