A railway bridge is 4620.8 meters long, a train is 160 meters long, and the speed of the train is 30 meters per second. How long does it take for the train to leave the bridge from the front of the train to the end of the bridge?
一座铁路桥长4620.8米，一列火车长160米，火车的速度是每秒30米，这列火车从车头上桥到车尾离开桥需要多长时间？
<gadget id="calculator">4_620.8 + 160</gadget>
<output>4_780.8</output>

<gadget id="calculator">4_780.8 / 30</gadget>
<output>159.36</output>

<result>159.36</result>