Question

If the radius of a sphere is doubled? What is the ratio of the surafce area of the original sphere to the new one?

Answer 1

Step-by-step explanation:

Let the original radius be r

so the original volume = 4/3πr³

new radius = 2r

so new volume = 4/3π (2r)³ = 4/3 π (8r³)

ratio = 4/3πr³/4/3π (8r³)

= r³ / 8r³ = 1/8

so the ratio is 1:8