To make a batch of parts, Master Wang can complete it in (1/4) hour alone, and Master Li can complete it in (1/2) hour alone. How many minutes can the two work together?
制作一批零件，王师傅独做(1/4)小时完成，李师傅独做(1/2)小时完成，两人合作几分钟可以完成？
<gadget id="calculator">1 / 15</gadget>
<output>1/15 = around 0.066667</output>

<gadget id="calculator">1 / 30</gadget>
<output>1/30 = around 0.033333</output>

<gadget id="calculator">(1/15) + (1/30)</gadget>
<output>1/10 = around 0.1</output>

<gadget id="calculator">1 / (1/10)</gadget>
<output>10</output>

<result>10</result>