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: by how much is 12 % of 24.2 more than 10 % of 14.2 ?
Options: a ) 0.1484 , b ) 14.84 , c ) 1.484 , d ) 2.762 , e ) none
[EX A]: c

[EX Q]: Problem: the average of the marks of 30 students in a class is 45 . if the marks of each student are doubled , find the new average ?
Options: a ) 85 , b ) 77 , c ) 33 , d ) 90 , e ) 75
[EX A]: d

[EX Q]: Problem: if the price of a book is first decreased by 25 % and then increased by 20 % , then the net change in the price will be :
Options: a ) 10 , b ) 388 , c ) 37 , d ) 29 , e ) 22
[EX A]:
a