There is a pool that can store 100 cubic meters of water. It has two water pipes, one for inlet and one for outlet. If the two water pipes are opened at the same time, the empty pool can be filled with water in a few minutes.
有一水池能储水100立方米，它有进、出两个水管，进水管每分钟进水8立方米，排水管每分钟排水3立方米．如果两个水管同时开，几分钟能将空池注满水．
<gadget id="calculator">8 - 3</gadget>
<output>5</output>

<gadget id="calculator">100 / 5</gadget>
<output>20</output>

<result>20</result>