There is a batch of parts that A alone takes 10 hours to produce, and B alone takes 5 hours more to complete than A. How many hours are they working together to complete?
有一批零件，甲单独生产要用10小时，乙单独做比甲多用5小时完成，两人合作多少小时完成？
<gadget id="calculator">1 / 10</gadget>
<output>1/10 = around 0.1</output>

<gadget id="calculator">1 / 15</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>