Two people, A and B, start from A to B at the same time, A rides a bicycle, B walks, and at the same time, C starts from B to A. A meets C after riding 16 kilometers, and B meets C after riding 12 kilometers. If A is cycling twice as fast as B is walking. So how many miles is the distance between A and B?
甲、乙两人同时从A地出发向B地前进，甲骑车，乙步行，与此同时，丙从B地出发向A地前进．甲骑16千米后与丙相遇，而乙走12千米后就与丙相遇．如果甲骑车的速度是乙步行速度的2倍．那么A，B两地相距多少千米？
<result>12</result>