Answer:
The answer is option b.
144π
Step-by-step explanation:
Surface area of a sphere is 4πr²
where r is the radius
diameter = radius / 2
For Big sphere
radius = 15 / 2 = 7.5in
Surface area = 4π(7.5)²
= 225π
Small sphere
radius = 9/2 = 4.5in
Surface area = 4π(4.5)²
= 81π
Difference of the surface areas is
Surface area of big sphere - surface area of small sphere
Which is
225π - 81π
= 144π
Hope this helps you.
