A city bus station governs three routes, bus No. 1 runs every 20 minutes, bus No. 2 runs every 30 minutes, bus No. 3 runs every 40 minutes, and the buses of the three routes depart at the same time at 6:00 in the morning , How many minutes later will the cars on these three routes drive simultaneously.
某城市公交汽车站管辖三条路线，1路车间隔20分钟开一辆，2路车间隔30分钟开一辆，3路车间隔40分钟开一辆，早上六点三条路线的车同时开出，再过多少分钟这三条路线上的车同时开．
<gadget id="calculator">2 * 2 * 2 * 3 * 5</gadget>
<output>120</output>

<result>120</result>