For a manuscript, it takes 3 hours for A to copy alone, 2 hours for B to copy alone, how many hours does it take for A and B to copy together.
一份稿件，甲单独抄要3小时完成，乙单独抄要2小时完成，甲、乙合抄要多少小时完成．
<gadget id="calculator">1 / 3</gadget>
<output>1/3 = around 0.333333</output>

<gadget id="calculator">1 / 2</gadget>
<output>1/2 = around 0.5</output>

<gadget id="calculator">(1/3) + (1/2)</gadget>
<output>5/6 = around 0.833333</output>

<gadget id="calculator">1 / (5/6)</gadget>
<output>6/5 = around 1.2</output>

<result>6/5 = around 1.2</result>