There is a large water inlet pipe on the top of a pool, and many small outlet pipes of the same size are installed on the bottom. Now there is half a pool of water in the pool. Open the water inlet pipe and 5 outlet pipes for 4 hours to drain the water in the pool. Open the water inlet pipe And 4 outlet pipes can drain the water in the pool in 6 hours, so how many hours can the pool be filled with the water inlet pipe and one outlet pipe?
有一个水池上面装有一个大进水管，下面装有很多大小一致的小出水管，现在水池里面有半池水，打开进水管和5个出水管4小时可以将水池的水放完，打开进水管和4个出水管6小时将水池的水放完，那么打开进水管和一个出水管多少小时可以将水池放满？
<gadget id="calculator">4 * 6</gadget>
<output>24</output>

<gadget id="calculator">4 * 5</gadget>
<output>20</output>

<gadget id="calculator">24 - 20</gadget>
<output>4</output>

<gadget id="calculator">6 - 4</gadget>
<output>2</output>

<gadget id="calculator">4 / 2</gadget>
<output>2</output>

<gadget id="calculator">4 - 2</gadget>
<output>2</output>

<gadget id="calculator">2 - 1</gadget>
<output>1</output>

<gadget id="calculator">6 / 1</gadget>
<output>6</output>

<gadget id="calculator">2 * 6</gadget>
<output>12</output>

<result>12</result>