The ratio of the radius of two circles is 2: 3, and then the ratio of their areas is?  Choices:
A) 1 : 7	B) 2 : 9	C) 4 : 9	D) 3 : 7	E) 3 : 4

Rationale: r 1 : r 2 = 2 : 3 î r 1 ^ 2 : î r 2 ^ 2 r 1 ^ 2 : r 2 ^ 2 = 4 : 9 answer : c
Answer: C