2007 AMC 12B Problem 1

Below is the professionally curated solution for Problem 1 of the 2007 AMC 12B, from LIVE by Po-Shen Loh. You can also try the full timed exam, view all 2007 AMC 12B solutions, or check the answer key.

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Concepts:perimeterarea

Difficulty rating: 900

1.

Isabella's house has 33 bedrooms. Each bedroom is 1212 feet long, 1010 feet wide, and 88 feet high. Isabella must paint the walls of all the bedrooms. Doorways and windows, which will not be painted, occupy 6060 square feet in each bedroom. How many square feet of walls must be painted?

678678

768768

786786

867867

876876

Solution:

The perimeter of each bedroom floor is 2(12+10)=442(12+10)=44 feet.

So the wall area in one bedroom is 44860=35260=29244\cdot8-60=352-60=292 square feet. Across all three bedrooms, Isabella paints 3292=8763\cdot292=876 square feet.

Thus, the correct answer is E.

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