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: the average ( arithmetic mean ) of 4 positive integers is 30 . if the average of 2 of these integers is 15 , what is the greatest possible value that one of the other 2 integers can have ? 
Options: a ) 55 , b ) 89 , c ) 100 , d ) 109 , e ) 115
[EX A]: b

[EX Q]: Problem: if n is an integer , f ( n ) = f ( n - 1 ) - n and f ( 4 ) = 14 . what is the value of f ( 6 ) ? 
Options: a ) 3 , b ) 0 , c ) 1 , d ) 2 , e ) 4
[EX A]: a

[EX Q]: Problem: the expression x # y denotes the product of the consecutive multiples of 3 between x and y , inclusive . what is the sum of the exponents in the prime factorization of 21 # 42 ? 
Options: a ) 23 , b ) 24 , c ) 25 , d ) 26 , e ) 27
[EX A]:
a