Spheres A and B have their radil 40 cm and 10 cm respectively. The ratio of the surface area of A to the surface area of B is	Pick:
A) 1 : 4
B) 1 : 16
C) 4 : 1
D) 16 : 1
E) none

Rationale: solution let the radil of a and b be r and r respectively . required ratio = 4 π r 2 / 4 π r 2 ‹ = › r 2 / r 2 ‹ = › ( r / r ) 2 ‹ = › ( 40 / 10 ) 2 ‹ = › 16 : 1 . answer d
Answer: D