GGUY wrote:

taken from GMAT PAPER TEST 55.

I know. It's simple. I'm searching for a method to do those questions. I "fell in love" with the double set matrix method, but i cannot apply it here correctly.

apart from solving this Q, I wonder how one knows how to approach thsoe word problems?

OA will folow.

In a sample of college students, 40 percent are third-year students and 70 percent are not second-year students. What fraction of those students who are not third-year students are second-year students?

(A) 3/4

(B) 2/3

(C) 4/7

(D) 1/2

(E) 3/7

let's put the total=100

third year:40

third year+first year=70 ===== first year = 30

second year=100-40-30=30

second year/first+second====30/60=1/2 OA D