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 sum of $ 1000 amounts to $ 1500 in 5 years at simple interest . if the interest rate is increased by 5 % it would amount to how much ? 
Options: a ) $ 1000 , b ) $ 750 , c ) $ 1541 , d ) $ 1478 , e ) $ 1750
[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 $ 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: the population of a town is 10000 . it decreases annually at the rate of 10 % p . a . what will be its population after 2 years ? 
Options: a ) 4300 , b ) 4500 , c ) 8100 , d ) 5230 , e ) 5366
[EX A]:
c