Question

A car covers $160km$ at a speed of $40km/hr$ and the next $120km$ at a speed of $60km/hr$ calculate its average speed.

Answer 1

As we know that

$\text{speed}=\frac{\text{distance}}{\text{time}}$

Time taken by the car t travel $160km$ when travelling with the speed of $40km/hr=\frac{160}{40}=4$ hour

Time taken by the car t travel $120km$ when travelling with the speed of $60km/hr=\frac{120}{60}=2$ hour

Now,

Total distance travelled by the car $=160+120=280km$

Total time taken $=4+2=6$ hours

Therefore,

Average speed $=\frac{\text{Total distance}}{\text{total time}}=\frac{280}{6}=46.67km/hr$