A, B, and C start from A to B, and the distance between A and B is 18.6 kilometers. It is known that A walks at 3 km/h, bikes at 15 km/h, B walks at 6 km/h, bikes at 15 km/h, and C walks at 5 km/h , the cycling speed is 18 km/h. Now there is only one bicycle. Please make reasonable arrangements to make A, B, and C arrive at B at the same time in the shortest time, so how many minutes will it take at least? (Cycling can bring people, but only one person.)
甲、乙、丙三人从A地出发向B地前进，A、B两地之间的距离为18.6千米．已知甲步行速度为3千米/时，骑车速度为15千米/时，乙步行速度为6千米/时，骑车速度为15千米/时，丙步行速度为5千米/时，骑车速度为18千米/时．现在只有一辆自行车，请通过合理安排使得甲、乙、丙在最短时间内同时到达B地，那么至少需要多少分钟？(骑车可以带人，但只能带一人．)
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