Question

The diameter of a wheel of a car is 98 cm. How many revolutions will it make to travel 6160 metres.

Answer 1

We have:
Diameter of the wheel of the car = 98 cm
∴ Circumference of the wheel of the car = $\mathrm{\pi d}=\left(\frac{22}{7}\times 98\right)\mathrm{cm}=308\mathrm{cm}$.
Note that, in one revolution of the wheel, the car travels a distance equal to the circumference of the wheel.

∴ The distance travelled by the car in one revolution of the wheel = 308 cm.
Total distance travelled by the car = 6160 m = 616000 cm.
​​∴ Number of revolutions = $\frac{616000}{308}=2000$.