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2007 AMC 12B Problem 1

Problem 1 of 25EasierGeometry

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?

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Solution

The perimeter of each bedroom floor is 2(12+10)=442(12+10)=44 feet. So the wall area in one bedroom is 44⋅8−60=352−60=29244\cdot8-60=352-60=292 square feet. Across all three bedrooms, Isabella paints 3⋅292=8763\cdot292=876 square feet. Thus, the correct answer is E.
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Tagged: perimeter · area

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