A wheel makes 1000 revolutions in covering a distance of 88 km. Find the radius of the wheel.

Distance covered in one revolution =  $\frac{88\times 1000}{1000}$= 88m. 

$2\mathrm{\pi R}2=88 \Rightarrow 2\times \frac{22}{7}\times R=88 \Rightarrow R=88\times \frac{7}{44}$