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'.

[EX Q]: Problem: a shopkeeper loses 15 % , if an article is sold for rs . 136 . what should be the selling price of the article to gain 20 % ?
Options: a ) s . 147 , b ) s . 148 , c ) s . 144 , d ) s . 189 , e ) s . 192
[EX A]: e

[EX Q]: Problem: a man buys an article for $ 10 . and sells it for $ 30 . find the gain percent ?
Options: a ) 25 % , b ) 50 % , c ) 20 % , d ) 150 % , e ) 300 %
[EX A]: e

[EX 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 $ 8,000 , what was its market value two years later ?
Options: a ) $ 8,000 , b ) $ 5,600 , c ) $ 3,200 , d ) $ 6,400 , e ) $ 800
[EX A]:
d