Question

A car covers 20 km in first hour of its journey, 40 km in next hour and 30 km in third hour. Calculate its average speed.

Answer 1

Average speed = $\frac{\mathrm{Total}\mathrm{distance}\mathrm{covered}}{\mathrm{Total}\mathrm{time}\mathrm{taken}}=\frac{20\mathrm{km}+30\mathrm{km}+40\mathrm{km}}{3\mathrm{h}}=\frac{90\mathrm{km}}{3\mathrm{h}}=30\mathrm{km}/\mathrm{h}$

The average speed of the car is 30 km/h.