Answer:
Average velocity is 0.296 m/s.
Average speed is 4.0 m/s.
Explanation:
Given:
Distance of the circular track is, 
Number of laps ran is, 
Time taken for the run is, 
Now, total distance covered in 5.4 laps = 
Also, since the path is a circle, the final position of the athlete after 5.4 laps will be 0.4 of 400 m ahead of the starting point.
Distance covered in 0.4 laps is, 
Therefore, the displacement of the athlete will be 160 m as the athlete is 160 m ahead of the starting point and displacement depends on the initial and final points only.
Now, average velocity is given as:

Average speed is the ratio of total distance covered to total time taken.
So, average speed = 