There are 300 trees in total. It takes 12 days for team A to plant alone, and 10 days for team B to plant alone. Now the two teams plant together, how many days can they finish planting?
一共有300棵树．甲队单独种需要12天，乙队单独种需要10天，现在两队合种，几天能种完？
<gadget id="calculator">1 / 12</gadget>
<output>1/12 = around 0.083333</output>

<gadget id="calculator">1 / 10</gadget>
<output>1/10 = around 0.1</output>

<gadget id="calculator">(1/12) + (1/10)</gadget>
<output>11/60 = around 0.183333</output>

<gadget id="calculator">1 / (11/60)</gadget>
<output>60/11 = around 5.454545</output>

<result>60/11 = around 5.454545</result>