• # question_answer A circular road runs around a circular ground. If the difference between the circumferences of the outer circle and the inner Circle is 66 metres, the width of the road is: $\left( Take\,\pi =\frac{22}{7} \right)$ A)  21 metres          B)  10.5 metres C)  7 metres           D)  5.25 metres

[b] Breadth of road $={{r}_{2}}-\,{{r}_{1}}$ ${{C}_{2}}-\,{{C}_{1}}=66$ $\therefore \,\,2\pi {{r}_{2}}=2\pi {{r}_{1}}=66$ $\Rightarrow 2\pi \,\,({{r}_{2}}-\,{{r}_{1}})=66$ $\Rightarrow {{r}_{2}}-\,{{r}_{1}}=\frac{66}{2\pi }=\frac{66\times 7}{2\times 22}=10.5\,\,metre$