A and B are walking towards each other along the railroad at the same speed. A train is coming, and it takes 8 seconds for the whole train to pass by A. After another 5 minutes, he drove past B with 7 clocks. How long will it take before A and B meet?
甲、乙两人沿铁路边相对而行，速度一样．一列火车开来，整个列车从甲身边驶过用8秒钟．再过5分钟后又用7钞钟从乙身边驶过．问还要经过多少时间，甲、乙两人才相遇？
<result>37.5</result>