Cars A and B depart from the east and west stations at the same time, meet for the first time at 80km away from the east station, return immediately after arriving at the station, and meet for the second time at 50km away from the west station. What is the distance in km between the east and west stations?
甲、乙两车同时从东西两站相对开出，第一次离东站80km处相遇，各车到站后立即返回，又在离西站50km处第二次相遇．东西两站的距离是多少km．
<gadget id="calculator">80 * 3</gadget>
<output>240</output>

<gadget id="calculator">240 - 50</gadget>
<output>190</output>

<result>190</result>