In this case we can say that he is traveling the same distance which two different speed that is 30 km per hour and 70 km per hour. Average speed is measured in units of distance per time and the average speed formula looks like this. Therefore the average speed would be the harmonic mean of the two speed or we can say that.
So if a particle covers a certain distance s in a time to then the average speed of the body is.
The formula for distance if you know time duration and the average speed is. And reached back to the point A traveled from point B at speed of 60 Mhr. The average speed is 48 Mhr. The average speed 2x30x70 3070 42 km per hour.