AMC10 2007 B

AMC10 2007 B · Q1

AMC10 2007 B · Q1. It mainly tests Arithmetic misc, Area & perimeter.

Isabella's house has 3 bedrooms. Each bedroom is 12 feet long, 10 feet wide, and 8 feet high. Isabella must paint the walls of all the bedrooms. Doorways and windows, which will not be painted, occupy 60 square feet in each bedroom. How many square feet of walls must be painted?

Isabella 的房子有 3 间卧室。每间卧室长 12 英尺，宽 10 英尺，高 8 英尺。Isabella 必须粉刷所有卧室的墙壁。每间卧室中有门窗占用 60 平方英尺，这些地方不需要粉刷。需要粉刷多少平方英尺的墙壁？

(A) 678 678

(B) 768 768

(D) 867 867

(E) 876 876

Answer

Correct choice: (E)

正确答案：（E）

Solution

The perimeter of each bedroom is 2(12 + 10) = 44 feet, so the surface to be painted in each bedroom has an area of 44 · 8 − 60 = 292 square feet. Since there are 3 bedrooms, Isabella must paint 3 · 292 = 876 square feet.

每间卧室的周长是 $2(12 + 10) = 44$ 英尺，因此每间卧室需要粉刷的墙面面积是 $44 · 8 − 60 = 292$ 平方英尺。有 3 间卧室，所以 Isabella 需要粉刷 $3 · 292 = 876$ 平方英尺。

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