A circular runway is 400 meters long. Xiao Wang runs 8 meters per second on average, and Lao Zhang runs 5 meters per second on average. Now Xiao Wang and Lao Zhang start from the starting point at the same time. How many seconds have passed since they met for the first time at the starting point?
一个环行跑道长400米，小王平均每秒跑8米，老张平均每秒跑5米，现小王和老张同时从起点出发，经过多少秒两人第一次在起点相遇．
<result>400</result>