Dayong and Xiaoyu are running on the circular track. It takes Dayong 60 seconds to run one lap, and Xiaoyu 90 seconds to run one lap. Now the two set off at the same time at the same place and in the same direction, and a few minutes later they meet again at the same place?
大勇和小宇在环形跑道上跑步，大勇跑一圈要60秒，小宇跑一圈要90秒．现在两人同时同地同向出发，几分钟后两人又在原地相会？
<result>3</result>