The cyclist covered a distance of 10 km in one direction at an average speed of 50 km / h

The cyclist covered a distance of 10 km in one direction at an average speed of 50 km / h, in the opposite direction at an average speed of 46 km / h. Determine the average speed for the entire journey.

Cyclist’s average speed:
Vav. = S / t, where S is the path covered by the cyclist (S = S1 + S2, where S1 = S2 = 10 km), t is the time the cyclist moved (t = t1 + t2).
t1 = S1 / V1, t2 = S2 / V2, where V1 is the speed in one direction (V1 = 50 km / h), V2 is the speed in the opposite direction (V2 = 46 km / h).
Vav. = S / t = (S1 + S2) / (S1 / V1 + S2 / V2) = (10 + 10) / (10/50 + 10/46) = 20 / 0.417 = 47.96 km / h.
Answer: The average speed of a cyclist is 47.96 km / h.