A, B, and C run and exercise. They all start from A at the same time, run to B, C, and D respectively, and then run back immediately. After running back to A, they run to B, C, and D respectively, and then immediately Run back to A, and keep running back and forth like this. The distance between B and A is (1/10) kilometers, the distance between C and A is (1/8) kilometers, and the distance between D and A is (3/16) kilometers. A runs 3.5 kilometers per hour, and B runs 4 thousand kilometers per hour. M, C runs 5 kilometers per hour. Question: If running back and forth like this, how many hours will it take for the three people to return to the starting point at the same time for the first time?
甲、乙、丙三人跑步锻炼，都从A地同时出发，分别跑到B、C、D三地，然后立即往回跑，跑回A地在分别跑到B、C、D，再立刻跑回A地，这样不停地来回跑．B与A相距(1/10)千米，C与A相距(1/8)千米，D与A相距(3/16)千米，甲每小时跑3.5千米，乙每小时跑4千米，丙每小时跑5千米．问：若这样来回跑，三人第一次同时回到出发点需用多少小时．
<gadget id="calculator">3_360 / 560</gadget>
<output>6</output>

<result>6</result>