1. The problem statement, all variables and given/known data A person walks from point a to point b at a speed of 5 m/s. Then she turns around and walks from point b to point a at a speed of 3 m/s. What is her average speed? 2. Relevant equations Average speed is equal to d/ change in t. 3. The attempt at a solution So I know the distance is 2d. I also know the acceleration is constant, though I don't know if I need it for the problem. So I tried to do 5m/s + 3m/s /2 to get the answer. That led to the wrong path. Since we don't have time, I'm assuming that maybe I use a kinematic equation. However, we don't know what acceleration is, other than it is constant.