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: what is the minimum percentage increase in the mean of set f { - 4 , - 1 , 0 , 6 , 9 } if its two smallest elements are replaced with two different primes ? 
Options: a ) 25 % , b ) 50 % , c ) 75 % , d ) 100 % , e ) 200 %
[EX A]: d

[EX Q]: Problem: for how many integer values of n will the value of the expression 4 n + 7 be an integer greater than 1 and less than 100 ? 
Options: a ) 30 , b ) 28 , c ) 27 , d ) 25 , e ) 26
[EX A]: d

[EX Q]: Problem: a multiple choice test consists of 4 questions , and each question has 5 answer choices . in how many e ways can the test be completed if every question is unanswered ? 
Options: a ) 24 , b ) 120 , c ) 625 , d ) 720 , e ) 1024
[EX A]:
c