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 of 13 numbers is 60 . average of the first 7 of them is 57 and that of the last 7 is 61 . find the 8 th number ?
Options: a ) 43 , b ) 30 , c ) 35 , d ) 45 , e ) 50

Output: a

Input: Consider Input: Problem: a number is doubled and 6 is added . if resultant is trebled , it becomes 72 . what is that number
Options: a ) 8 , b ) 10 , c ) 9 , d ) 14 , e ) 16

Output: c

Input: Consider Input: Problem: if a person walks at 10 km / hr instead of 5 km / hr , he would have walked 20 km more . the actual distance traveled by him is ?
Options: a ) 50 km , b ) 76 km , c ) 20 km , d ) 16 km , e ) 97 km
Output: c