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'.

Example Input: Problem: how many multiples of 2 are there between 10 and 52 , 10 and 52 inclusive ? 
Options: a ) 27 , b ) 25 , c ) 24 , d ) 21 , e ) 22
Example Output: e

Example Input: Problem: in a group of ducks and cows , the total number of legs are 22 more than twice the no . of heads . find the total no . of buffaloes . 
Options: a ) 11 , b ) 12 , c ) 13 , d ) 15 , e ) 16
Example Output: a

Example Input: Problem: the average age of 37 students in a group is 14 years . when teacher ' s age is included to it , the average increases by one . what is the teacher ' s age in years ? 
Options: a ) 35 years , b ) 45 years , c ) 51 years , d ) 52 years , e ) none of these
Example Output:
d