Two trains, fast and slow, are 150 meters long and 200 meters long respectively, and they are running opposite each other on a straight track. If the person sitting on the fast train sees the slow train passing by the window for 8 seconds, then the person sitting on the slow train sees the fast train passing by. How many seconds is the window time?
快慢两列火车分别长150米和200米，相向行驶在平直的轨道上，若坐在快车上的人看见慢车驶过窗口的时间是8秒，则坐在慢车上的人看见快车驶过窗口的时间是多少秒？
<gadget id="calculator">200 / 8</gadget>
<output>25</output>

<gadget id="calculator">150 / 25</gadget>
<output>6</output>

<result>6</result>