In this task, you need to answer the given multiple-choice question on the gain. Gain is the value by which to multiply the input. Classify your answers into 'a', 'b', 'c', 'd', and 'e'.

[EX Q]: Problem: if 45 % of z is 96 % of y and y is 75 % of x , what percent of x is z ? 
Options: a ) 200 , b ) 160 , c ) 100 , d ) 65 , e ) 50
[EX A]: b

[EX Q]: Problem: a particular library has 75 books in a special collection , all of which were in the library at the beginning of the month . these book are occasionally loaned out through an inter - library program . if , by the end of the month , 80 percent of books that were loaned out are returned and there are 67 books in the special collection at that time , how many books of the special collection were loaned out during that month ? 
Options: a ) 20 , b ) 30 , c ) 35 , d ) 40 , e ) 55
[EX A]: d

[EX Q]: Problem: if 45 % of a class averages 95 % on a test , 50 % of the class averages 78 % on the test , and the remainder of the class averages 60 % on the test , what is the overall class average ? ( round final answer to the nearest percent ) . 
Options: a ) 83 % , b ) 84 % , c ) 85 % , d ) 86 % , e ) 87 %
[EX A]:
c