please help me with these!! I don’t understand

This question is incomplete, the complete question is;

Katie Ledecky swims the length of a 50m Olympic size pool in 25 seconds and swims the return trip to the starting position in 26 seconds. What are her average velocities during:

a) The first half of the swim?

b) The second half of the swim?

a) her average velocities during the first half = 2 m/s

b) her average velocities during the second half = 1.923 m/s

Step-by-step explanation:

Given that;

displacement = 50 m

time taken t = 25 secs

a)

average velocity = displacement / time taken = 50 / 25 = 2 m/s

Therefore her average velocities during the first half = 2 m/s

b)

In the second half;

displacement = 50 m

time taken t = 26 secs

average velocity = displacement / time taken = 50 / 26 = 1.923 m/s

Therefore her average velocities during the second half = 1.923 m/s