Bunuel wrote:

The ratio of the ages of A and B is 7 : 11. Which of the following can be the ratio of their ages after 5 years?

(A) 1 : 3

(B) 9 : 20

(C) 4 : 15

(D) 3 : 5

(E) 2 : 3

We may recall the rule that if any ratio a/b, in which a is less than b, and a positive constant is added to both the numerator and denominator of the fraction, then the resulting fraction is greater than the original one.

We see that 7/11 is around 0.63, and since 2/3 = 0.667, we see that 2/3 is the only ratio that is larger than 0.63.

Answer: E

_________________

Scott Woodbury-Stewart

Founder and CEO

GMAT Quant Self-Study Course

500+ lessons 3000+ practice problems 800+ HD solutions