A train is 150 meters long and travels 19 meters per second. How many seconds does it take for the whole train to pass through a 420-meter bridge?
一列列车长150米，每秒行19米，全车通过420米的大桥，需要多少秒．
<gadget id="calculator">150 + 420</gadget>
<output>570</output>

<gadget id="calculator">570 / 19</gadget>
<output>30</output>

<result>30</result>