The skier goes down from the mountain 50 m in 5 s. Descending from the mountain and continuing to move

The skier goes down from the mountain 50 m in 5 s. Descending from the mountain and continuing to move, he goes to a full stop for another 30 m in 15 s. Find the average speed of the skier over the entire movement.

S1 = 50 m.
S2 = 30 m.
t1 = 5 s.
t2 = 15 s.
Vav -?
Average speed Vav is determined by the formula: Vav = S / t. Where S is the entire distance that the body has traveled in time t.
S = S1 + S2.
t = t1 + t2.
Vav = (S1 + S2) / (t1 + t2).
Vav = (50 m + 30 m) / (5 s + 15 s) = 4 m / s.
Answer: the average speed of the skier is Vav = 4 m / s.