**Question:**

The diameters of front and rear wheels of a tractor are 80 cm and 2m, respectively. Find the number of revolutions that rear wheel will make in covering

a distance in which the front wheel makes 1400 revolutions.

**Solution:**

Given, diameter of front wheels, d1 = 80 cm

and diameter of rear wheels, d2 = 2 m = 200 cm

$\therefore \quad$ Radius of front wheel $\left(r_{1}\right)=\frac{80}{2}=40 \mathrm{~cm}$

$\therefore \quad$ Circumference of the front wheel $=2 \pi r_{1}=\frac{2 \times 22}{7} \times 40=\frac{1760}{7}$

$\therefore$ Total distance covered by front wheel $=1400 \times \frac{1760}{7}=200 \times 1760$

$=352000 \mathrm{~cm}$

Number of revolutions by rear wheel $=\frac{\text { Distance coverd }}{\text { Circumference }}$

$=\frac{352000}{2 \times \frac{22}{7} \times 100}=\frac{7 \times 3520}{2 \times 22}=\frac{24640}{44}=560$