Xiao Ming stores water in a 17-meter reservoir. The reservoir has two pipes: one inlet pipe and one outlet pipe. The inlet pipe can raise the water level by 3 meters per hour, and the outlet pipe can lower the water level by 2 meters per hour. If the inlet and outlet pipes are open at the same time, how many hours will it take to fill the tank?
小明给一个17米的蓄水池蓄水，蓄水池有两根管：一根进水管和一根出水管．进水管每小时可使水位上升3米，出水管每小时可使水位下降2米．如果进水管和出水管同时开放，多少小时才可以蓄满水池？
<gadget id="calculator">3 - 2</gadget>
<output>1</output>

<gadget id="calculator">17 / 1</gadget>
<output>17</output>

<result>17</result>