project, built by engineering team A, needs 20 days to complete; built by engineering team B, it takes 1.5 times as many days as engineering team A to complete. How many days will it take for the two teams to complete the joint cultivation?
一项工程，由甲工程队修建，需要20天完成；由乙工程队修建，需要的天数是甲工程队的1.5倍才能完成．两队合修共需要多少天完成？
<gadget id="calculator">1 / 20</gadget>
<output>1/20 = around 0.05</output>

<gadget id="calculator">20 * 1.5</gadget>
<output>30</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>

<gadget id="calculator">1 / (1/12)</gadget>
<output>12</output>

<result>12</result>