A pool can hold 84 tons of water, and there are two water injection pipes for water injection. The pool can be filled in 8 hours by opening the A pipe alone, and it can be filled in 6 hours by opening the B pipe alone. Now open two water pipes at the same time, how many hours can the pool be filled?
一个水池可容水84吨，有两个注水管注水，单开甲管8小时可将水池注满，单开乙管6小时可注满．现在同时打开两个水管，几小时后可注满水池的？
<gadget id="calculator">1 / 8</gadget>
<output>1/8 = around 0.125</output>

<gadget id="calculator">1 / 6</gadget>
<output>1/6 = around 0.166667</output>

<gadget id="calculator">(1/8) + (1/6)</gadget>
<output>7/24 = around 0.291667</output>

<gadget id="calculator">1 / (7/24)</gadget>
<output>24/7 = around 3.428571</output>

<result>24/7 = around 3.428571</result>