Question

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。每间卧室中不需要粉刷的门洞和窗户占 $60$ 平方英尺。需要粉刷多少平方英尺的墙？

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?

$678$

$768$

$786$

$867$

$876$

答案：E

知识点：表面积周长

难度评级：720

解答：

一间卧室的墙面面积为 $2(12+10)\cdot 8 = 44\cdot 8 = 352$ 平方英尺。减去门洞和窗户的 $60$ 平方英尺，每间卧室需粉刷 $352-60=292$ 平方英尺。

有 $3$ 间卧室，所以共需粉刷 $3\cdot 292 = 876$ 平方英尺。

所以正确答案是 E。

The walls of one bedroom have area $2(12+10)\cdot 8 = 44\cdot 8 = 352$ square feet. Subtracting the $60$ square feet of doorways and windows leaves $352-60=292$ square feet per bedroom.

With $3$ bedrooms, the total is $3\cdot 292 = 876$ square feet.

Thus, the correct answer is E.

2007 AMC 10B 第 1 题

答案：E

难度评级：720

解答：

其他年份的第 1 题