The product of x and y is a constant. If the value of x is increased by 80%, by what percentage must the value of y be decreased?
Choices:
A) 45%  B) 55%  C) 35%  D) 40%  E) 44.44%
x*y = constt.   Let x = y = 100 in beginning   i.e. x*y = 100*100= 
<gadget id="calculator">100*100</gadget>
<output>10_000</output>
10000   x (100) ---becomes---&gt; 1.8x (180)   i.e. 180*New 'y'= 10000   i.e. New 'y' = 10000/180 = 55.55   i.e. y decreases from 100 to 55.55 i.e. Decrease of 44.44%   Answer: option 44.44%
<result>E</result>
The product of x and y is a constant. If the value of x is increased by 80%, by what percentage must the value of y be decreased?