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: 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
[EX A]: d

[EX Q]: Problem: a man took loan from a bank at the rate of 12 % p . a . s . i . after 3 years he had to pay rs . 5400 interest only for the period . the principal amount borrowed by him was ? 
Options: a ) 15002 , b ) 15001 , c ) 15000 , d ) 15007 , e ) 15009
[EX A]: c

[EX Q]: Problem: calculate the amount that an investor needs to be invest to earn $ 1023 in interest in 24 months if the investor plans to invest x dollars in a savings account that pays interest at an annual rate of 12 % compounded semi - annually ? 
Options: a ) 3980 , b ) 3600 , c ) 3700 , d ) 3800 , e ) 3900
[EX A]:
e