AMC8 2016

AMC8 2016 · Q12

AMC8 2016 · Q12. It mainly tests Fractions, Averages (mean).

Jefferson Middle School has the same number of boys and girls. Three-fourths of the girls and two-thirds of the boys went on a field trip. What fraction of the students on the field trip were girls?

杰斐逊中学男孩和女孩数量相同。\frac{3}{4}的女孩和\frac{2}{3}的男孩参加了实地考察旅行。实地考察旅行中的学生有女孩占几分之几？

(A) $1/2$ $1/2$

(B) $9/17$ $9/17$

(D) $2/3$ $2/3$

(E) $14/15$ $14/15$

Answer

Correct choice: (B)

正确答案：（B）

Solution

Converting the given fractions to the same denominator, we see that $9/12$ of the girls and $8/12$ of the boys went on the trip. So the ratio of the number of girls to the number of boys was $9:8$, and it follows that $9/17$ of the students on the trip were girls.

将给定分数通分后，有 $9/12$ 的女生和 $8/12$ 的男生参加了旅行。因此女生人数与男生人数的比是 $9:8$，从而参加旅行的学生中有 $9/17$ 是女生。

Topics