A long-distance bus station distributes one vehicle every 20 to the east line, and one vehicle to the west line every 15. If the trains are sent to the two lines at the same time, how many minutes must pass before the trains depart at the same time.
某长途汽车站向东线每20分发一辆车，向西线每15分发一辆车，如果同时向两线发车，至少要经过多少分又同时发车．
<gadget id="calculator">2 * 2 * 3 * 5</gadget>
<output>60</output>

<result>60</result>