The radii of two circles are 12 cm and 4 cm respectively. The radius of the circle whose circumference equals the sum of the circumferences of the two circles is
A
8 cm
B
16 cm
C
6 cm
D
None of these
Correct Option:
B
Explanation
Circumference is 2πr. The sum of the circumferences of circles with radii 12 cm and 4 cm is 2π(12) + 2π(4) = 2π(16). Therefore the radius of a single circle with the same circumference is 16 cm.
