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: in a certain pond , 80 fish were caught , tagged , and returned to the pond . a few days later , 50 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 ) 400 , b ) 625 , c ) 1,250 , d ) 2,000 , e ) 10,000

Output: d


Input: Consider Input: Problem: the price of a t . v . set worth rs . 15000 is to be paid in 20 installments of rs . 1500 each . if the rate of interest be 6 % per annum , and the first installment be paid at the time of purchase , then the value of the last installment covering the interest as well will be ? 
Options: a ) 29997 , b ) 28088 , c ) 13500 , d ) 19000 , e ) 2799

Output: c


Input: Consider Input: Problem: what sum of money will produce rs . 75 as simple interest in 4 years at 3 1 / 2 percent ? 
Options: a ) 337 , b ) 500 , c ) 266 , d ) 288 , e ) 536


Output: e