Question

一个房间里三分之二的人坐在四分之三的椅子上。剩下的人站着。如果有 $6$ 把空椅子，房间里有多少人？

Two-thirds of the people in a room are seated in three-fourths of the chairs. The rest of the people are standing. If there are $6$ empty chairs, how many people are in the room?

$12$

$18$

$24$

$27$

$36$

答案：D

知识点：分数比与比例

难度评级：1230

小提示：

空椅子是所有椅子的剩余四分之一

The empty chairs are the remaining one-fourth of the chairs.

大提示：

坐着的人是所有人的三分之二

The seated people are two-thirds of all the people.

解答：

因为 $\frac{3}{4}$ 的椅子被坐了，所以 $6$ 把空椅子是所有椅子的 $\frac{1}{4}$ 。因此共有 $24$ 把椅子。

坐着的人数是 $\frac{3}{4}$ 乘 $24$ ，即 $18$ 。

这 $18$ 个坐着的人是所有人的 $\frac{2}{3}$ ，所以总人数为 $18\div\frac23=27$ 。

所以正确答案是 D。

Since $\frac{3}{4}$ of the chairs are occupied, the $6$ empty chairs are $\frac{1}{4}$ of all the chairs. Thus there are $24$ chairs.

The number of seated people is $\frac{3}{4}$ of $24,$ which is $18.$

Those $18$ seated people are $\frac{2}{3}$ of all the people, so the total number of people is $18\div\frac23=27.$

Thus, D is the correct answer.

2004 AMC 8 第 20 题

答案：D

难度评级：1230

小提示：

大提示：

解答：

其他年份的第 20 题