There are three people A, B, and C. A walks 100 meters per minute, B walks 120 meters per minute, and C walks 70 meters per minute. If the three people walk in the same direction at the same time and start from the same place, they will walk along a circle with a circumference of 300 meters. Walking on the shaped track, then a few minutes later, the three of them can meet again?
有甲、乙、丙三个人，甲每分钟行走100米，乙每分钟行走120米，丙每分钟行走70米，如果三个人同时同向，从同地出发，沿周长是300米的圆形跑道行走，那么几分钟之后，三个人又可以相聚？
<gadget id="calculator">100 - 70</gadget>
<output>30</output>

<gadget id="calculator">300 / 30</gadget>
<output>10</output>

<gadget id="calculator">300 / 10</gadget>
<output>30</output>

<result>30</result>