9. (10 points) Person A and Person B are jogging on a 300-meter track in the playground. They start at the same time and in the same direction, with A behind B at the start. A first overtakes B after 12 minutes, and overtakes B again at 32 minutes. Assuming both maintain a constant speed, how many meters behind B was A at the start?
【Solution】Solve:
$$
\begin{array}{l}
12 \div(32-12)=\frac{3}{5} \\
300 \times \frac{3}{5}=180 \text { (meters) }
\end{array}
$$

So the answer is 180