Question

The circumferences of two concentric circles are $176$ metres and $132$ metres respectively. What is the difference between their radii?
(take $\pi =\frac{22}{7}$)

Answer 1

If $R$ and R' be the radii of two circles
$\therefore 2\pi R-2R^{\prime }=176-132$
$2\pi (R-R^{\prime })=44$
$\therefore R-R^{\prime }=\frac{44\times 7}{2\times 22}=7m$