It takes 25 seconds for the train to pass through the 250-meter-long tunnel, and 23 seconds to pass through the 210-meter-long tunnel. It is also known that there is a truck in the same direction as the train in front of the train. The length of the truck body is 320 meters and the speed is 17 meters per second. How many seconds does it take from meeting to leaving the truck.
列车通过250米长的隧道用25秒，通过210米长的隧道用23秒，又知列车的前方有一辆与它行驶方向相同的货车，货车车身长320米，速度为每秒17米，列车与货车从相遇到离开需多少秒．
<gadget id="calculator">250 - 210</gadget>
<output>40</output>

<gadget id="calculator">25 - 23</gadget>
<output>2</output>

<gadget id="calculator">40 / 2</gadget>
<output>20</output>

<gadget id="calculator">20 * 25</gadget>
<output>500</output>

<gadget id="calculator">500 - 250</gadget>
<output>250</output>

<gadget id="calculator">250 + 320</gadget>
<output>570</output>

<gadget id="calculator">20 - 17</gadget>
<output>3</output>

<gadget id="calculator">570 / 3</gadget>
<output>190</output>

<result>190</result>