1. The problem statement, all variables and given/known data A person walks first at a constant speed 5m/s along a straight line from point A to point B, and then back along the line from B to A at a constant speed 3m/s. (a) What is her average speed over the entire trip? (b) Her average velocity over the entire trip? 2. Relevant equations Average speed = total distance traveled / total time 3. The attempt at a solution (b) is obviously 0 since start and end positions are the same. For (a), the book gives the answer 3.75m/s. No idea how this came about. Since no time was given, how do you get this answer???