There are 300 saplings in total, it takes 8 days for team A to plant alone, and 10 days for team B to plant alone. Now the two teams work together. How many days can it be planted?
一共有300棵树苗，甲队单独种需要8天，乙队单独种需要10天．现在两队合作．几天能种完？
<gadget id="calculator">1 / 8</gadget>
<output>1/8 = around 0.125</output>

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

<gadget id="calculator">(1/8) + (1/10)</gadget>
<output>9/40 = around 0.225</output>

<gadget id="calculator">1 / (9/40)</gadget>
<output>40/9 = around 4.444444</output>

<result>40/9 = around 4.444444</result>