A water tank is being filled and emptied simultaneously by two pipes. Pipe A fills the tank at a rate of 3 liters per minute, while Pipe B empties it at a rate of 2 liters per minute. If the tank has an initial volume of 50 liters, how long will it take to fill the tank to 100 liters? Let's think step by step and output the final answer within \boxed{}.
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