Exams › SSC CGL (Prelims) › General
The radii of three concentric circles are in arithmetic progression. If the innermost radius is 7 cm and the outermost radius is 21 cm, what is the radius of the middle circle?
- 12 cm
- 11 cm
- 10 cm
- 14 cm
Correct answer: 14 cm
Solution
Since the three radii are in arithmetic progression, the middle radius is the average of the first and third radii. So, \((7+21)/2 = 14\) cm.
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