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 sum of three consecutive multiples of 3 is 108 . what is the largest number ? 
Options: a ) 36 , b ) 39 , c ) 33 , d ) 30 , e ) 42
[EX A]: b

[EX Q]: Problem: find value of x : ( 422 + 404 ) ^ 2 − ( 4 × 422 × 404 ) = x . 
Options: a ) 234 , b ) 267 , c ) 324 , d ) 356 , e ) 577
[EX A]: c

[EX Q]: Problem: a 6 - liter solution is 40 % alcohol . how many liters of pure alcohol must be added to produce a solution that is 50 % alcohol ? 
Options: a ) 1.2 , b ) 1.5 , c ) 1.8 , d ) 2.1 , e ) 2.4
[EX A]:
a