Ruz
Last Activity: 3 Years ago
By definition, the average speed is given by-
We already know the total distance travelled, which is: 40km+ 80km= 120km
For calculating time, we use the equation s=v*t or t=s/v
that is, time taken= distance/speed
For first part, time taken, t1= 40/20= 2 hours
For second part, time taken, t2= 80/40= 2 hours
So total time= 4 hours
Putting this is our formula, avg speed= total distance/total time
We get, avg speed= 120/4= 30 km/h
