In this task, you need to answer the given multiple-choice question on the gain. Gain is the value by which to multiply the input. Classify your answers into 'a', 'b', 'c', 'd', and 'e'.

[Q]: Problem: the owner of a furniture shop charges his customer 25 % more than the cost price . if a customer paid rs . 8340 for a computer table , then what was the cost price of the computer table ? 
Options: a ) rs . 6672 , b ) rs . 6727 , c ) rs . 6908 , d ) rs . 6725 , e ) rs . 6728
[A]: a


[Q]: Problem: the market value of a certain machine decreased by 10 percent of its purchase price each year . if the machine was purchased in 1982 for its market value of $ 8000 , what was its market value two years later ? 
Options: a ) $ 8,000 , b ) $ 5,600 , c ) $ 3,200 , d ) $ 6,400 , e ) $ 800
[A]: d


[Q]: Problem: the first half of the 20 th century , the population of a particular country increased by 200 percent . in the second half of the century , the population increased by 300 percent . what was the percent increase for the 20 th century as a whole ? 
Options: a ) 500 % , b ) 600 % , c ) 800 % , d ) 1100 % , e ) 1200 %
[A]:
d