It takes 17 seconds for a train to pass through a 650-meter bridge. The length of the train is 200 meters. What is the speed of the train in meters per second?
一列火车完全通过650米的大桥需要17秒，火车长200米，火车的速度是每秒多少米．
<gadget id="calculator">650 + 200</gadget>
<output>850</output>

<gadget id="calculator">850 / 17</gadget>
<output>50</output>

<result>50</result>