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: what is the value of 10 ^ 7 - 6 ^ 5 ? 
Options: a ) 99 , 91,223 , b ) 99 , 92,224 , c ) 99 , 94,265 , d ) 99 , 95,300 , e ) 99 , 96,307
[EX A]: b

[EX Q]: Problem: for a certain exam , a score of 60 was 2 standard deviations below mean and a score of 100 was 3 standard deviations above mean . what was the mean score for the exam ? 
Options: a ) 74 , b ) 76 , c ) 78 , d ) 80 , e ) 82
[EX A]:
b