Question 1184116
<br>
As the other tutors who responded both said, the statement of the problem does not allow us to answer the questions.<br>
"speed" and "velocity" are both measurements at a specific time; there is nothing in the statement of the problem that tells us anything about his speed or velocity at any one time.<br>
Note also that "speed per second" is a nonsensical phrase....<br>
The intent of the problem is clearly to determine the AVERAGE speed and the AVERAGE velocity, and presumably to explain the difference between the two.<br>
For average speed, he traveled 750+250=1000 meters in 13 seconds; his average speed was 1000/13 meters per second.<br>
For average velocity, the calculation is the total displacement divided by the time.  Since he ended up only 500 meters from his starting point, his average velocity was 500/13 meters per second.<br>
NB.... 1000 meters in 13 seconds is a rather fast "walk"....!<br>