There are two trains, one train is 180 meters long and travels an average of 15 meters per second, and the other train is 150 meters long and travels an average of 18 meters per second. How long did it take for the two trains to meet and separate?
有两列火车，一列火车长180米，平均每秒行驶15米，另一列火车长150米，平均每秒行驶18米．两列火车从相遇到相离一共用了多长时间？
<gadget id="calculator">180 + 150</gadget>
<output>330</output>

<gadget id="calculator">15 + 18</gadget>
<output>33</output>

<gadget id="calculator">330 / 33</gadget>
<output>10</output>

<result>10</result>