Question

How does the volume of a cone change if the height is doubled ?

Answer 1

answer is b)2/3 pie r^2 h

Answer 2

If you keep the radius the same and double the height, you find that by experimentation with this a few times, doubles your volume as well.  That means that instead of 1/3 pi r^2 h, we will have 2/3 pi r^2 h.  Your answer B.