A tunnel is 360 meters long. It took a certain train 8 seconds from the front of the train to enter the tunnel and 20 seconds from the entrance of the train to the exit of the whole train. How long is this train?
一条隧道长360米，某列火车从车头入洞到全车进洞用了8秒钟，从车头入洞到全车出洞共用了20秒钟．这列火车长多少米？
<gadget id="calculator">20 - 8</gadget>
<output>12</output>

<gadget id="calculator">360 / 12</gadget>
<output>30</output>

<gadget id="calculator">30 * 8</gadget>
<output>240</output>

<result>240</result>