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?  Pick one: A) 5.7 B) 6.0 C) 6.7 D) 10.2 E) 18.0
Let r= Radius of smaller circle. Let R = Radius of larger circle   Therefore:   2πr + 2πR = 64   where 2r = R   Thus:   2πr + 4πr = 64   6πr = 64   r = approx 3.4   πR + 2Rπ = 64   3πR = 64   R = approx 6.8   r + R = approx 10.2   Answer 10.2
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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?