Sal knows the volume of a cylinder is 500 cubic units. He wants to create a cylinder with twice the volume. Which variation of the original cylinder will have a volume of exactly 1,000 cubic units? Use the same radius but double the height.
Use the same height but double the radius.
Double the radius and double the height.
Use the same height but quadruple the radius.

Someone please give me an answer to this instead of saying that it's not that hard.