Question

The radius of the large sphere is twice
the radius of the small sphere.​

Answer 1

40 cm²

Explanation:

Given the ratio of radii = a : b , then

ratio of areas = a² : b²

Here ratio of radii = 1 : 2

ratio of areas = 1² : 2² = 1 : 4

Thus

surface area of large sphere = 4 × 10 = 40 cm²