The circular runway is 400 meters long. Li Ming and Wang Wei started from the same place at the same time. Li Ming ran 300 meters per minute, and Wang Wei ran 250 meters per minute. After how many minutes, they ran at the same place for the second time.
环形跑道一周长400米，李明和王伟从同一处同时起跑，李明每分跑300米，王伟每分跑250米，多少分钟后两人第二次跑在同一处．
<gadget id="calculator">300 - 250</gadget>
<output>50</output>

<gadget id="calculator">400 / 50</gadget>
<output>8</output>

<result>8</result>