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'.

Example Input: Problem: each of the integers from 0 to 9 , inclusive , is written on a separate slip of blank paper and the ten slips are dropped into a hat . if 5 of the slips are the drawn , without replacement , what is the probability that all 5 have a even number written on it ? 
Options: a ) 1 / 252 , b ) 1 / 10 , c ) 1 / 8 , d ) 1 / 2 , e ) 5 / 9
Example Output: a

Example Input: Problem: in an election between two candidates , one got 60 % of the total valid votes , 30 % of the votes were invalid . if the total number of votes was 9000 , the number of valid votes that the other candidate got , was : 
Options: a ) 2500 , b ) 2520 , c ) 3000 , d ) 3100 , e ) none of these
Example Output: b

Example Input: Problem: a shopkeeper loses 15 % , if an article is sold for rs . 153 . what should be the selling price of the article to gain 20 % ? 
Options: a ) s . 147 , b ) s . 248 , c ) s . 244 , d ) s . 229 , e ) s . 216
Example Output:
e