11. (3 points) Xiaopang used two stopwatches to measure the speed of a train. He found that this train took 40 seconds to pass over a 660-meter-long bridge, and it took 10 seconds to pass by him at the same speed. Please calculate the length of the train based on the data provided by Xiaopang. $\qquad$ meters.
【Solution】According to the analysis, we have:
$$
\begin{array}{l}
660 \div(40-10), \\
=660 \div 30, \\
=22 \text { (meters); } \\
22 \times 10=220 \text { (meters); }
\end{array}
$$

Answer: The length of the train is 220 meters. Therefore, the answer is: 220.