Workers build a road, team A can repair this road every day (1/20), team B can repair this road every day (1/30), the two teams jointly repair, how much of this road can be repaired every day.
工人师傅修一条路，甲队每天能修这条路的(1/20)，乙队每天能修这条路的(1/30)，两队合修，每天能修这条路的多少．
<gadget id="calculator">1 / 20</gadget>
<output>1/20 = around 0.05</output>

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

<gadget id="calculator">(1/20) + (1/30)</gadget>
<output>1/12 = around 0.083333</output>

<result>1/12 = around 0.083333</result>