In this task, you need to answer the given multiple-choice question on the general math. Classify your answers into 'a', 'b', 'c', 'd', and 'e'.

Ex Input:
Problem: a man has some hens and cows . if the number of heads be 60 and the number of feet equals 200 , then the number of hens will be : 
Options: a ) 22 , b ) 25 , c ) 24 , d ) 20 , e ) 28

Ex Output:
d


Ex Input:
Problem: a & b started a partnership business . a ' s investment was thrice the investment of b and the period of his investment was two times the period of investments of b . if b received rs 5000 as profit , what is their total profit ? 
Options: a ) 28000 , b ) 30000 , c ) 32000 , d ) 35000 , e ) none of these

Ex Output:
d


Ex Input:
Problem: a library has an average of 600 visitors on sundays and 240 on other days . the average number of visitors per day in a month of 30 days beginning with a sunday is : 
Options: a ) 250 , b ) 260 , c ) 300 , d ) 285 , e ) none

Ex Output:

c