The cyclist covered 20 km in 2 hours, and 24 km in the next 2 hours. Find the average speed.

S1 = 20 km.
t1 = 2 h.
S2 = 24 km.
t2 = 2 h.
Vav -?
To find the average speed of a cyclist’s movement Vav, it is necessary to divide the entire path S traveled by the time of his movement t along the entire path: Vav = S / t.
The path S, which the cyclist traveled, will be the sum: S = S1 + S2, where S1 is the path of the first part of the path, S2 is the path of the second part of the path.
S = 20 km + 24 km = 44 km.
The travel time of the entire path is expressed by the sum: t = t1 + t2, where t1 is the time of movement on the first part of the path, t2 is the time of movement on the second part of the path.
t = 2 hours + 2 hours = 4 hours.
Vav = 44 km / 4 h = 11 km / h.
Answer: the average speed of a cyclist is Vav = 11 km / h.