To build a section of road, section A alone takes 10 days to complete, and team B alone takes 15 days to complete. If the two teams work together, how many days will it be completed?
修一段路，甲段单独修要10天完成，乙队单独修要15天完成．如果两队合修，多少天修完？
<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>