A, B, and C are three people. A walks 120 meters per minute, B walks 100 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 runway, after a few minutes, can the three of them meet again?
甲、乙、丙三个人，甲每分钟行走120米，乙每分钟行走100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，那几分钟之后，三个人又可以相聚？
<result>30</result>