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'.

Input: Consider Input: Problem: the average marks of a class of 30 students is 40 and that of another class of 50 students is 60 . find the average marks of all the students ? 
Options: a ) 82.5 , b ) 52.9 , c ) 52.2 , d ) 52.5 , e ) 52.7

Output: d


Input: Consider Input: Problem: marcella has 27 pairs of shoes . if she loses 9 individual shoes , what is the greatest number of matching pairs she could have left ? 
Options: a ) 22 , b ) 20 , c ) 19 , d ) 16 , e ) 15

Output: a


Input: Consider Input: Problem: a man â € ™ s current age is ( 2 / 5 ) of the age of his father . after 14 years , he will be ( 1 / 2 ) of the age of his father . what is the age of father at now ? 
Options: a ) 40 , b ) 45 , c ) 38 , d ) 50 , e ) 70


Output: e