Two cars, A and B, start from A and B at the same time and drive towards each other. A takes 15 minutes to reach B, and B takes 1 hour to reach A. The speed of A is how many times the speed of B.
甲乙两辆车分别从A，B两地同时出发，相向而行，甲经过15分钟到达B地，乙经过1小时到达A地，则甲车的速度是乙车的速度的多少倍．
<gadget id="calculator">4 / 1</gadget>
<output>4</output>

<result>4</result>