Question

Raub 女士班上有 $28$ 名学生，女生比男生多四人。班上女生人数与男生人数之比是多少？

There are four more girls than boys in Ms. Raub's class of $28$ students. What is the ratio of the number of girls to the number of boys in her class?

$3 : 4$

$4 : 3$

$3 : 2$

$7 : 4$

$2 : 1$

答案：B

知识点：比与比例一次方程

难度评级：770

解答：

设班上男生人数为 $x$ ，则女生有 $x + 4$ 人。因为共有 $28$ 名学生， $\begin{align*} x + x + 4 &= 28\\ 2x&=24 \\ x&=12. \end{align*}$ 因此女生与男生之比为 $16 : 12 = 4 : 3$ 。

所以正确答案是 B。

Let $x$ be the number of boys in the class. This means that there are $x + 4$ girls. As there are $28$ students, we know that: $\begin{align*} x + x + 4 &= 28\\ 2x&=24 \\ x&=12. \end{align*}$ Therefore, the ratio of girls to boys is $16 : 12 = 4 : 3.$

Thus, B is the correct answer.

2014 AMC 8 第 7 题

答案：B

难度评级：770

解答：

其他年份的第 7 题