The capacity of a certain pool is 100 cubic meters. It has two inlet pipes A and B and one drain pipe. It takes 10 hours and 15 hours for the two pipes A and B to fill the pool respectively. There is some water in the pool. If A and B If the two pipes B are filled with water and the drain pipe is drained, it will take 6 hours to drain the water in the pool. So how many cubic meters of water is in the pool?
某水池的容量是100立方米，它有甲、乙两根进水管和一根排水管，甲、乙两管单独注满水池分别需要10小时和15小时，水池中原有一些水，如果甲、乙两管同时进水而排水管放水，需要6小时将池中的水放完，如果甲管进水而排水管放水需2小时将池中的水放完．那么池中原有水多少立方米．
<gadget id="calculator">100 / 10</gadget>
<output>10</output>

<gadget id="calculator">20 / 3</gadget>
<output>20/3 = around 6.666667</output>

<gadget id="calculator">10 + (20/3)</gadget>
<output>50/3 = around 16.666667</output>

<gadget id="calculator">(50/3) * 6</gadget>
<output>100</output>

<gadget id="calculator">10 * 2</gadget>
<output>20</output>

<gadget id="calculator">100 - 20</gadget>
<output>80</output>

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

<gadget id="calculator">80 / 4</gadget>
<output>20</output>

<gadget id="calculator">20 * 2</gadget>
<output>40</output>

<gadget id="calculator">40 - 20</gadget>
<output>20</output>

<result>20</result>