MathRevolution wrote:

[GMAT math practice question]

When \(\frac{x}{y} = 2.6\), \(\frac{(x-y)}{(x+y)}=?\)

\(A. \frac{2}{7}\)

\(B. \frac{3}{8}\)

\(C. \frac{4}{9}\)

\(D. \frac{5}{9}\)

\(E. \frac{7}{10}\)

GIVEN: x/y = 2.6

Scan the answer choices (

ALWAYS scan the answer choices before formulating a solution)....

All of them are in fraction form. So....

Rewrite 2.6 as a fraction: x/y = 2 3/5

Or...: x/y = 13/5

So, let's let x =

13 and y =

5, since these values satisfy the condition that x/y = 13/5

Our goal is to find the value of (x - y)/(x + y)

Plug in x =

13 and y =

5We get: (x - y)/(x + y) = (

13 -

5)/(

13 +

5)

= 8/18

= 4/9

Answer: C

Cheers,

Brent

_________________

Brent Hanneson – Founder of gmatprepnow.com