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 cost price of 50 articles is equal to the selling price of 15 articles , then the gain or loss percent is ? 
Options: a ) 16 , b ) 127 , c ) 12 , d ) 18 , e ) 233
[EX A]: e

[EX Q]: Problem: a can complete a certain job in 19 days . b is 90 % more efficient than a . in how many days can b complete the same job ? 
Options: a ) 6 , b ) 6.25 , c ) 7 , d ) 7.5 , e ) 10
[EX A]: e

[EX Q]: Problem: if 60 % of 3 / 5 of a number is 36 , then the number is ? 
Options: a ) 80 , b ) 100 , c ) 75 , d ) 90 , e ) none of these
[EX A]:
b