It takes 10 hours for the master to process a batch of parts alone, which is (1/2) more per hour than the apprentice. How many hours did the two work together?
一批零件，师傅单独加工要10小时，每小时比徒弟多加工(1/2)．两人合作几小时完成？
<gadget id="calculator">1 / 10</gadget>
<output>1/10 = around 0.1</output>

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

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

<gadget id="calculator">(1/10) / (3/2)</gadget>
<output>1/15 = around 0.066667</output>

<gadget id="calculator">(1/10) + (1/15)</gadget>
<output>1/6 = around 0.166667</output>

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

<result>6</result>