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'.

Input: Consider Input: Problem: some of 50 % - intensity red paint is replaced with 20 % solution of red paint such that the new paint intensity is 40 % . what fraction of the original paint was replaced ? 
Options: a ) 1 / 3 , b ) 1 / 5 , c ) 2 / 3 , d ) 3 / 4 , e ) 4 / 5

Output: a


Input: Consider Input: Problem: the population of a town is 10000 . it increases annually at the rate of 27 % p . a . what will be its population after 2 years ? 
Options: a ) 14000 , b ) 14400 , c ) 16129 , d ) 14600 , e ) 14700

Output: c


Input: Consider Input: Problem: a man has $ 10,000 to invest . he invests $ 4000 at 5 % and $ 3500 at 4 % . in order to have a yearly income of $ 500 , he must invest the remainder at 
Options: a ) 6 % , b ) 6.1 % , c ) 6.2 % , d ) 6.3 % , e ) 6.4 %


Output: e