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 Q]: Problem: how many positive integers less than 100 have a remainder of 6 when divided by 13 ? 
Options: a ) 2 , b ) 7 , c ) 6 , d ) 9 , e ) 10
[EX A]: c

[EX Q]: 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
[EX A]: a

[EX Q]: Problem: the number obtained by interchanging the digits of a two - digit number is less than the original number by 36 . the sum of the digits of the number is 8 . what is the original number ? 
Options: a ) 71 , b ) 62 , c ) 53 , d ) 35 , e ) 45
[EX A]:
b