求助一道数学题GWD4-20

精灵宝宝 · 发表于 2010-10-24 21:49:06

Q20:

Of the students in a certain school, 15 percent are enrolled in an art class and 10 percent are enrolled in a music class. What percent of the students in the school are enrolled in neither an art class nor a music class?

(1)2/3 of the students who are enrolled in an art class are also enrolled in a music class.

(2) There are more than 100 students in the school.

A. Statement (1) ALONE is sufficient, but statement (2) alone is not sufficient.

B. Statement (2) ALONE is sufficient, but statement (1) alone is not sufficient.

C. BOTH statements TOGETHER are sufficient, but NEITHER statement ALONE is sufficient.

D. EACH statement ALONE is sufficient.

E. Statements (1) and (2) TOGETHER are NOT sufficient.

答案选A 我没有疑问，但是想问的是在（1）的情况下，只选择了music的学生是不是没有呀？（0%）
因为同时选择了art和music的占10%，10%-10%=0

coocooper · 发表于 2010-10-24 21:51:18

是的。我也算得是没有，选了music class的学生都选了art.

simpleru · 发表于 2010-10-24 21:55:17

不会啊。both的是15%*（2/3).
music 选择的人数比例是 10%
那么，music alone 的人数比例就是 10%- （15%*（2/3)）

simpleru · 发表于 2010-10-24 21:56:13

哦！不对啊~hehehhe 那么不就是10%-10%？

精灵宝宝 · 发表于 2010-10-24 21:58:23

呵呵看来我想的没错

求助一道数学题GWD4-20

所属分类: GMAT考试

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