The ratio of the radius of two circles is 1: 9, and then the ratio of their areas is?	Answers
A) 1 : 8
B) 1 : 6
C) 1 : 9
D) 1 : 3
E) 1 : 81

Rationale: "r 1 : r 2 = 1 : 9 π r 12 : π r 22 r 12 : r 22 = 1 : 81 answer : e"
Answer: E