The motorcyclist was driving at a speed of 80 km / h halfway. and the rest of the way – at a speed of 60 km / h.

The motorcyclist was driving at a speed of 80 km / h halfway. and the rest of the way – at a speed of 60 km / h. What was the average speed of a motorcyclist along the way?

Let’s denote half of the path as S, then the entire path is equal to 2S.
Let’s find the time at each site.
t1 = S / 80
t2 = S / 60
Vav = All the way / all the time = 2S / (S / 80 + S / 60) = 2S * 240 / 7S = 480/7 = 68.5 km / h