A cuboid pool is 50 meters long, 20 meters wide and 1.5 meters deep. If the pump is used to drain the water, the water will be 2.5 cubic meters per minute. How many hours does it take to drain the water?
一个长方体水池，长50米，宽20米，池内水深1.5米．如果用水泵向外排水，每分排水2.5立方米．排完水需要多少小时？
<result>10</result>