To process a batch of parts, A alone can complete it in 12 hours, and B alone can complete it in 10 hours. How many hours can A and B work together to complete half of this batch of parts?
加工一批零件，甲独做12小时完成，乙独做10小时完成．甲乙合做多少小时能完成这批零件的一半？
<gadget id="calculator">1 / 2</gadget>
<output>1/2 = around 0.5</output>

<gadget id="calculator">1 / 12</gadget>
<output>1/12 = around 0.083333</output>

<gadget id="calculator">1 / 10</gadget>
<output>1/10 = around 0.1</output>

<gadget id="calculator">(1/12) + (1/10)</gadget>
<output>11/60 = around 0.183333</output>

<gadget id="calculator">(1/2) / (11/60)</gadget>
<output>30/11 = around 2.727273</output>

<result>30/11 = around 2.727273</result>