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: a man is 24 years older than his son . in six years , his age will be twice the age of his son . the present age of the son is 
Options: a ) 14 years , b ) 28 years , c ) 20 years , d ) 22 years , e ) none
[EX A]: e

[EX Q]: Problem: if the remainder is 15 when the integer n is divided by 28 , what is the remainder when 2 n is divided by 14 ? 
Options: a ) 0 , b ) 1 , c ) 2 , d ) 3 , e ) 4
[EX A]: c

[EX Q]: Problem: find the average of all prime numbers between 12 and 24 . 
Options: a ) 30 , b ) 33.6 , c ) 18 , d ) 20 , e ) none
[EX A]:
c