A certain bus station is the starting point of buses No. 1 and No. 3. After the first bus departs at the same time at 6:00 in the morning, No. 1 bus departs every 15 minutes, and No. 3 bus departs every 12 minutes. ． At least how much time has passed before the two cars start at the same time?
某公共汽车站是1路和3路汽车的起点站，从早上6：00同时各发出第一辆车后，1路车每隔15分钟发一辆，3路车每隔12分钟发一辆．至少经过多少时间两辆车又同时出发？
<gadget id="calculator">2 * 2 * 3 * 5</gadget>
<output>60</output>

<result>60</result>