C becauseaks135 wrote:If x,y and z are integers, is x+y+2z even?
a) x+z is even
b) y+z is even
[spoiler]OA: C[/spoiler]
Can someone please explain why?[/spoiler]
a)x+z=even
x+y+2z=(x+z)+(y+z) we need to know whether y+z is even or odd
NOT SUFFICIENT
b) same as above- not sufficient
combine both
(x+z)+(y+z)=even +even=even
