13. Two people, A and B, are moving uniformly along a circular track with a circumference of 400 meters. A takes 4 minutes to walk one lap, while B takes 7 minutes. They start at the same time, place, and direction. After A completes 10 laps, A changes to the opposite direction. After starting, every time A catches up with B or meets B head-on, both clap to signal. Question: When the two people clap for the 15th time, how much time has A walked? How much distance has B walked?
13、A walked for $66 \frac{2}{11}$ minutes, B walked $3781 \frac{9}{11}$ meters.