Question

一条笔直的混凝土人行道宽 $3$ 英尺，长 $60$ 英尺，厚 $3$ 英寸。如果混凝土必须按整立方码订购，承包商至少需要订购多少立方码混凝土？

A straight concrete sidewalk is to be $3$ feet wide, $60$ feet long, and $3$ inches thick. How many cubic yards of concrete must a contractor order for the sidewalk if concrete must be ordered in a whole number of cubic yards?

$2$

$5$

$12$

$20$

多于 $20$

more than $20$

答案：A

知识点：体积单位换算

难度评级：1140

解答：

厚度 $3$ 英寸 $= \dfrac14$ 英尺，所以体积是 $3 \cdot 60 \cdot \dfrac14 = 45$ 立方英尺。

因为 $1$ 立方码 $= 27$ 立方英尺，所以体积是 $\dfrac{45}{27} = 1\dfrac23$ 立方码。按整立方码订购时必须向上取整，需订购 $2$ 立方码。

所以正确答案是 A。

The thickness is $3$ inches $= \dfrac14$ foot, so the volume is $3 \cdot 60 \cdot \dfrac14 = 45$ cubic feet.

Since $1$ cubic yard $= 27$ cubic feet, this is $\dfrac{45}{27} = 1\dfrac23$ cubic yards. Rounding up to a whole number, the contractor must order $2$ cubic yards.

Thus, the correct answer is A .

1990 AMC 8 第 17 题

答案：A

难度评级：1140

解答：

其他年份的第 17 题