Question

Calculate and compare the surface area of sphere A
, which has a radius of 2 in., and sphere B
, which has a radius of 10 in. The formula for the surface area of a sphere is 4πr2
.(1 point)
Responses

Sphere A
has a surface area of 2π in.2
and sphere B
has a surface area of 10π in.2
, meaning sphere B
’s surface area is 4 times as large as sphere A
’s.
Sphere upper A has a surface area of 2 pi in. squared and sphere upper B has a surface area of 10 pi in. squared , meaning sphere upper B ’s surface area is 4 times as large as sphere upper A ’s.

Sphere A
has a surface area of 4π in.2
and sphere B
has a surface area of 100π in.2
, meaning sphere B
’s surface area is 25 times as large as sphere A
’s.
Sphere upper A has a surface area of 4 pi in. squared and sphere upper B has a surface area of 100 pi in. squared , meaning sphere upper B ’s surface area is 25 times as large as sphere upper A ’s.

Sphere A
has a surface area of 8π in.2
and sphere B
has a surface area of 40π in.2
, meaning sphere B
’s surface area is 5 times as large as sphere A
’s.
Sphere upper A has a surface area of 8 pi in. squared and sphere upper B has a surface area of 40 pi in. squared , meaning sphere upper B ’s surface area is 5 times as large as sphere upper A ’s.

Sphere A
has a surface area of 16π in.2
and sphere B
has a surface area of 400π in.2
, meaning sphere B
's surface area is 25 times as large as sphere A
’s.

Answer 1

Use SA = 4πr^2.

Sphere A: 4π(2^2) = 4π(4) = 16π in^2.
Sphere B: 4π(10^2) = 4π(100) = 400π in^2.

Ratio: 400π / 16π = 25, so sphere B's surface area is 25 times sphere A's.

The correct choice is the one giving 16π in^2 and 400π in^2 (B is 25× A).