What is the average velocity during the first 2 seconds

What is the average velocity during the first 2 seconds?

time (s) 0, 1, 2, 3, 4, 5
position (m) 0, 20, 50, 130, 150, 200

please explain in details.. how come the answer is 25 m/s

Total distance traveled in first two seconds = 50-0 = 50 m; Time lapsed = 2-0 = 2 s
So average velocity = 50/2 = 25 m/s

well at 2 seconds the position travels to 50
and at 0 seconds that position is at 0

to find the velocity (average speed) we need to find how fast it it takes

so 'distance 2s - distance 0s / time 2s - time 0s = velocity'
(50 - 0)/ (2 - 0)
= 50/2
=25 m/s

velocity is the average speed, so in 2 seconds it travels 50meters
so per second it travels 25m (for the first 2 seconds)