A project can be completed by team A alone in 12 days, team B alone in 6 days, how many days will the two teams work together to complete.
一项工程，甲队单独干12天完成，乙队单独干6天完成，两队合干多少天完成．
<gadget id="calculator">1 / 12</gadget>
<output>1/12 = around 0.083333</output>

<gadget id="calculator">1 / 8</gadget>
<output>1/8 = around 0.125</output>

<gadget id="calculator">(1/12) + (1/8)</gadget>
<output>5/24 = around 0.208333</output>

<gadget id="calculator">1 / (5/24)</gadget>
<output>24/5 = around 4.8</output>

<result>24/5 = around 4.8</result>