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'.

[Q]: Problem: a number is doubled and 6 is added . if resultant is trebled , it becomes 72 . what is that number 
Options: a ) 8 , b ) 10 , c ) 9 , d ) 14 , e ) 16
[A]: c


[Q]: Problem: x varies inversely as square of y . given that y = 3 for x = 1 . the value of x for y = 6 will be equal to : 
Options: a ) 3 , b ) 6 , c ) 1 / 4 , d ) 1 / 3 , e ) 9
[A]: c


[Q]: Problem: set a contains all the even numbers between 42 and 90 inclusive . set b contains all the even numbers between 62 and 110 inclusive . what is the difference between the sum of elements of set b and the sum of the elements of set a ? 
Options: a ) 300 , b ) 350 , c ) 400 , d ) 450 , e ) 500
[A]:
e