New GRE Math Q

[mkamony]

Hi everyone! This is my first post here :)

I have a q from the new GRE OG page 151

Among the 9000 people attending a football game at College C, there were x students from College C and y students who were not from College C.

A) The number of people attending the game who were not students

B) 9000- x- y

The answer to this one is C. but my q is what if there're other segments of students among the 9000, like z students who play guitar, so shouldn't the answer be D?

Thanks ahead

[jen]

Hi there,

If there are "z students who play the guitar," those students would still have to go to College C or not, right? Regardless of what other properties a student has, all students have to either attend College C or not, so x + y really is the sum of all the students.

It's like if I said that a month had 30 days, and x is the number of days on which it rained, and y is the number on which it did not rain. It might also be that some of the days were days that it snowed, or that there was a parade! But every single day would still fall into the x or y category.

Sincerely,
Jen