The surface area of a sphere is same as the curved surface area of a right circular cylinder whose height and diameter are 12 cm each. The radius of the sphere is:
Pick.
A) 4 cm
B) 6 cm
C) 8 cm
D) 10 cm
E) 9 cm

Rationale: "explanation : curved surface area of sphere = 4 / π r 2 surface area of cylinder = 2 π rh = > 4 / π r 2 = 2 π rh = > r 2 = 6 ∗ 12 / 2 = > r 2 = 36 = > r = 6 note : diameter of cylinder is 12 so radius is taken as 6 . option b"
Answer: B