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: if the simple interest on a certain sum of money for 5 years is one – fifth of the sum , then the rate of interest per annum is 
Options: a ) 4 % , b ) 7 % , c ) 6 % , d ) 4 % , e ) 3 %
[EX A]: d

[EX Q]: Problem: the present population of a town is 200 . population increase rate is 10 % p . a . find the population of town after 1 years ? 
Options: a ) 100 , b ) 120 , c ) 200 , d ) 220 , e ) 250
[EX A]: d

[EX Q]: Problem: fresh grapes contain 75 % water by weight and raisins obtained by drying fresh grapes contain 25 % water by weight . how many kgs of fresh grapes are needed to get 25 kgs of raisins ? 
Options: a ) 75 kgs , b ) 64 kgs , c ) 72 kgs , d ) 65 kgs , e ) 70 kgs
[EX A]:
a