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: if 213 × 16 = 3408 , then 16 × 21.3 is equal to : 
Options: a ) 0.3408 , b ) 3.408 , c ) 34.08 , d ) 340.8 , e ) none of these
[EX A]: d

[EX Q]: Problem: when positive integer m is divided by positive integer n , the remainder is 12 . if m / n = 24.2 , what is the value of n ? 
Options: a ) 120 , b ) 60 , c ) 30 , d ) 24 , e ) 12
[EX A]: b

[EX Q]: Problem: the overall age of x and y is 10 year greater than the overall age of y and z . z is how many decades younger that x ? 
Options: a ) 11 , b ) 10 , c ) 12 , d ) 17 , e ) 19
[EX A]:
b