Carcass wrote:

The quantities S and T are positive and are related by the equation S = k/T, where k is a constant. If the value of S increases by 50 percent, then the value of T decreases by what percent?

A) 25%

B) 33 and \(\frac{1}{3}%\)

C) 50%

D) 66 and \(\frac{2}{3}\)%

E) 75%

Another approach it to first find some values that satisfy the condition that S = K/T

How about S = 2, K = 2 and T = 1 (since 2 = 2/1)

Now what happens to T if we increase S by 50%?

Well, if we increase 2 (the value of T) by 50%, we get S = 3

K is constant, so K = 2 (still)

What must T equal?

Take S = K/T and plug in the new value of S to get 3 = 2/T (and now solve for T)

To do so, multiply both sides by T to get: 3T = 2

Now divide both sides by 3 to get: T = 2/3

So, the value of T has DECREASED from 1 to 2/3

This represents a 33 1/3% decrease

Answer: B

Cheers,

Brent

_________________

Brent Hanneson – Creator of greenlighttestprep.com

Sign up for our free GRE Question of the Day emails