The diameter of a large sphere is 4 times the diameter of a small sphere. The surface area of the large sphere is how many times the surface area of small sphere?

Surface Area of a Sphere = 4π (d/2) ²

Let the smaller sphere's diameter be just a sample of 4 units in diameter and let the large spheres diameter be 4 times that of the smaller sphere.

Small Sphere: 4π (4/2) ² = 16π units²

Large Sphere: 4π (16/2) ² = 256π units²

256π / 16π = 16 times

The large sphere has a surface area 16 times that of the smaller one.