A train of passenger trains and a train of freight trains start from A and B at the same time and run towards each other. It is known that the passenger trains travel 80 kilometers per hour and the freight trains travel 60 kilometers per hour. After 2.5 hours, the distance between the two vehicles is still 50 kilometers. Find the length of the railway between two stations.
一列客车与一列货车同时从A，B两站出发，相向而行，已知客车每时行80千米，货车每时行60千米，2.5时后，两车还相距50千米．求两站之间的铁路长．
<gadget id="calculator">80 + 60</gadget>
<output>140</output>

<gadget id="calculator">140 * 2.5</gadget>
<output>350</output>

<gadget id="calculator">350 + 50</gadget>
<output>400</output>

<result>400</result>