The ratio of the radii is 2:1, so the ratio of their surface areas is 4:1. The area of a sphere is defined by 4 * pi * r^2
So if the radius of the first sphere is 2r, then it would be (2r)^2 = 4r^2
The rest is the same. So the ratio of their surface areas would be
4 * pi * 4r^2 divided by
4 * pi * r^2
or 4.
