A cuboid swimming pool is 50m long and 25m wide. When all the water inlet pipes are opened, 5m**2 of water can be injected per minute. If the water depth is to reach 1.5m, how many hours must be filled?
一个长方体游泳池，长50m，宽25m，打开全部进水管，每分钟可注入5m**2的水，如果要使水深达到1.5m，须注水多少小时？
<result>6.25</result>