Question

a car travels 40 km at an average speed of 80 km per hour and then Travels 40 km at an average speed of 40 km per hour the average speed of the car for the 80 km is

Answer 1

The total distance travelled is 80 km.

Half distance (40 km) is travelled at 80 km/h and the remaining half distance (40km) is travelled at 40 km/h.

Time used:

Formula : t=d/v

t=40/80=0.5 hour or 1/2 hour

t=40/40=1 hour

Total time taken = 1.5 hour

Now,

Speed = distance/time = 80/1.5 = 53.33 km/h

Answer : 53.33 km/h

Answer 2

average speed = 2V1V2/V1+V2

=2*80*40/40+80

=160/3Km/h