A wheel of a car makes$500$ revolutions in $11km$. Find the diameter of the wheel. 

 

Distance covered in 500 revolutions $=11km =(11\times 100000)cm$ .

So, distance covered in 1 revolution $= 11\times \frac{100000}{500 }=2200 cm$ . 

We know, the circumference = distance covered by wheel in one revolution

  $\pi d = 2200$ , $d =\frac{2200}{\mathrm{\pi }}= \frac{2200 }{{\displaystyle \frac{22}{7}}}=2200\times \frac{7}{22} =700 cm$ . 

So, the diameter of the wheel is $700 cm.$