task, team A alone can complete this task every day (1/20), team B alone needs 12 days to complete this task, if two teams cooperate to complete this task (1/20), how many days will it take ?
一件工作，甲队独做每天能完成这件工作的(1/20)，乙队单独完成这件工作需要12天，如果两队合作完成这件工作的(1/20)，需要多少天？
<gadget id="calculator">1 / 20</gadget>
<output>1/20 = around 0.05</output>

<gadget id="calculator">1 / 12</gadget>
<output>1/12 = around 0.083333</output>

<gadget id="calculator">(1/20) + (1/12)</gadget>
<output>2/15 = around 0.133333</output>

<gadget id="calculator">(1/20) / (2/15)</gadget>
<output>3/8 = around 0.375</output>

<result>3/8 = around 0.375</result>