The first thing you should know is that the distance is equal to the speed per time. Therefore if You walk forward at 1.5 m / s for 8s d = 1.5t [0,8] s Your friend decides to walk faster and starts at 2.0 m / s for the first 4 s. d = 2t [0,4] s Then she slows down and walks forward at 1.0 m / s for the next 4s d = t + 4 [4,8] s Who walked farther? They both walked the same distance 12 meters