To build a road, team A builds this road every day (1/10), and team B builds this road every day (1/15). How many days will it take for the two teams to work together?
修一条路，甲队每天修这条路的(1/10)，乙队每天修这条路的(1/15)．两队合修，几天修完？
<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>