Bus No. 1 departs every 6 minutes, and Bus No. 2 departs every 10 minutes. After the two buses depart at the same time, at least how many minutes will they depart at the same time?
1路公共汽车每6分钟发一班车，2路公用汽车每10分钟发一班车．这两路公共汽车同时发车后，至少多少分钟后同时发车？
<gadget id="calculator">2 * 3 * 5</gadget>
<output>30</output>

<result>30</result>