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: on a sum of money , the simple interest for 2 years is rs . 324 , while the compound interest is rs . 340 , the rate of interest being the same in both the cases . the rate of interest is 
Options: a ) 15 % , b ) 14.25 % , c ) 9.87 % , d ) 10.5 % , e ) 11.5 %
[EX A]: c

[EX Q]: Problem: in a certain pond , 40 fish were caught , tagged , and returned to the pond . a few days later , 40 fish were caught again , of which 2 were found to have been tagged . if the percent of tagged fish in the second catch approximates the percent of tagged fish in the pond , what is the approximate number of fish in the pond ? 
Options: a ) 1000 , b ) 625 , c ) 1,250 , d ) 2,500 , e ) 10,000
[EX A]: a

[EX Q]: Problem: the salary of a typist was at first raised by 10 % and then the same was reduced by 5 % . if he presently draws rs . 4180 . what was his original salary ? 
Options: a ) 2277 , b ) 2999 , c ) 4000 , d ) 2651 , e ) 1971
[EX A]:
c