<image>【Question】A reservoir is 120 meters long, 30 meters wide, and 3 meters deep. There are two water pipes installed by the side of the reservoir. First, the first water pipe is opened, and after several hours, the second water pipe is opened. The following line chart shows the change in water volume within the reservoir. Observe the chart before answering the questions.
(1) From the chart, both pipes are _____ pipes. (fill in “inlet” or “outlet”)
(2) How many cubic meters of water does the first inlet pipe inject per hour?
(3) How many cubic meters of water does the second inlet pipe inject per hour?
(4) If both pipes are opened from the start, how many hours would it take to fill the entire reservoir?
(5) Consideration: If the first pipe is an inlet pipe and the second pipe is an outlet pipe, after how long will the reservoir be emptied if the second pipe is opened 5 hours after the first pipe starts operating?