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 Input:
Problem: what will be the difference between simple and compound interest @ 20 % per annum on a sum of $ 500 after 2 years ? 
Options: a ) $ 10 , b ) $ 20 , c ) $ 25 , d ) $ 30 , e ) $ 40

Ex Output:
b


Ex Input:
Problem: a sum was put at si at certain rate for 2 years . had it been put at 3 % higher rate , it would have fetched rs . 300 more . find the sum 
Options: a ) rs 4000 , b ) rs 5000 , c ) rs 6000 , d ) rs 7000 , e ) rs 8000

Ex Output:
b


Ex Input:
Problem: jackie has two solutions that are 2 percent sulfuric acid and 12 percent sulfuric acid by volume , respectively . if these solutions are mixed in appropriate quantities to produce 60 liters of a solution that is 10 percent sulfuric acid , approximately how many liters of the 12 percent solution will be required ? 
Options: a ) 18 , b ) 20 , c ) 48 , d ) 36 , e ) 42

Ex Output:

c