The overall age of X and Y is 12 year greater than the overall age of Y and Z. Z is how many decades younger that X?
Choose the correct choice from the following options
A) 11  B) 15  C) 12  D) 17  E) 19
12   12   (X + Y) – (Y + Z) = 12   X – Z = 12
<result>C</result>
The overall age of X and Y is 12 year greater than the overall age of Y and Z. Z is how many decades younger that X?