answer: (e) 9/8
the volume of a cylinder is 1/3(h)(r^2)(pi).
so, if we have x as the height of cylinder A and y as the height of cylinder B ...
volume cylinder A = (16/3)(x)(pi)
volume cylinder B = (36/3)(y)(pi)
and since volume B = 2 (volume A), if we plug in what we calculated, we have...
2(16/3)(x)(pi) = (36/3)(y)(pi)
(2)(16)x = 36y
32x=36y
8x = 9y
thus the answer is e, as if we plug in x = 9 and y = 8 into our equation, we get 72 = 72 which is true.