For a project, after 10 days of cooperation between teams A and B, there are still some left. The rest will take 20 days for team A to repair alone, and 30 days for team B to repair alone. If A and B cooperate in this project, how many days will it take to complete the task?
一项工程，甲乙两队合做10天后，还剩下一些．剩下的如果给甲队单独修要20天，如果让乙队单独修则要30天．如果这项工程让甲乙合做，一共要多少天才能完成任务？
<gadget id="calculator">10 + 15 + 30</gadget>
<output>55</output>

<gadget id="calculator">1 / 55</gadget>
<output>1/55 = around 0.018182</output>

<gadget id="calculator">3 / 110</gadget>
<output>3/110 = around 0.027273</output>

<gadget id="calculator">(1/55) + (3/110)</gadget>
<output>1/22 = around 0.045455</output>

<gadget id="calculator">1 / (1/22)</gadget>
<output>22</output>

<result>22</result>