A batch of parts can be processed by worker A in (1/2) hours alone, worker B can be processed in (2/3) hours alone, and how many hours will it take for two workers to process them together?
一批零件，甲工人单独加工要(1/2)小时完成，乙工人单独加工(2/3)小时完成，两人一起加工，需要多少小时完成？
<gadget id="calculator">1 / 2</gadget>
<output>1/2 = around 0.5</output>

<gadget id="calculator">1 / (1/2)</gadget>
<output>2</output>

<gadget id="calculator">2 / 3</gadget>
<output>2/3 = around 0.666667</output>

<gadget id="calculator">1 / (2/3)</gadget>
<output>3/2 = around 1.5</output>

<gadget id="calculator">2 + (3/2)</gadget>
<output>7/2 = around 3.5</output>

<gadget id="calculator">1 / (7/2)</gadget>
<output>2/7 = around 0.285714</output>

<result>2/7 = around 0.285714</result>