If 3x=9y=z, what is x+y, in terms of z?  Choose the correct choice from the following choices.
A) z/2 B) 2z C) z/3 D) 3z/5 E) 4z/9
3x=9y=z   x = z/3   and y = z/9   x+y = z/3 + z/9 = 4z/9   Answer is 4z/9
<result>E</result>
If 3x=9y=z, what is x+y, in terms of z?