Thread: Quantitative reasoning

Hello,

another quantitative reasoning question from my GRE booklet that I desperately need help with :

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

a) 25%
b) 33 1/3 %
c) 50%
d) 66 2/3 %
e) 75%

Any suggestions appreciated !

pick some easy values to work with ...

let S = 2

k = 6

T = 3

T = k/S

3 = 6/2

increase S by 50% ...

T = 6/3

T = 2

T changes from 3 to 2 ... a 33 1/3 % decrease

Originally Posted by fsiwaju

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

a) 25%
b) 33 1/3 %
c) 50%
d) 66 2/3 %
e) 75%

If and are positive and , then must be a positive constant.
So, let's assign positive numerical values to , , and such that .
For example, let , and .

These values work for .

Then,

and , which is a decrease of .