The total circumference of two circles is 64. If the first circle has a circumference that is exactly twice the circumference of the second circle, then what is the approximate sum of their two radii? Answers:	A) 5.7	B) 6.0	C) 6.7	D) 10.2	E) 18.0

Rationale: let r = radius of smaller circle . let r = radius of larger circle therefore : 2 π r + 2 π r = 64 where 2 r = r thus : 2 π r + 4 π r = 64 6 π r = 64 r = approx 3.4 π r + 2 r π = 64 3 π r = 64 r = approx 6.8 r + r = approx 10.2 answer d
Answer: D