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'.

[Q]: Problem: if a large pizza has a radius that is 10 % larger that that of a medium pizza , what is the percent increase in area between a medium and a large pizza ? 
Options: a ) 15 % , b ) 21 % , c ) 25 % , d ) 30 % , e ) 36 %
[A]: b


[Q]: Problem: if a lends rs . 2000 to b at 10 % per annum and b lends the same sum to c at 11.5 % per annum then the gain of b in a period of 3 years is ? 
Options: a ) 90 , b ) 122.5 , c ) 132.5 , d ) 114.5 , e ) 212.5
[A]: a


[Q]: Problem: how many pounds of salt at 50 cents / lb must be mixed with 40 lbs of salt that costs 38 cents / lb so that a merchant will get 20 % profit by selling the mixture at 48 cents / lb ? 
Options: a ) 2 , b ) 5 , c ) 8 , d ) 15 , e ) 25
[A]:
c