To build a waterway, two teams, A and B, can complete it in 10 days. After the two teams cooperate for 4 days, the rest will be repaired by Team A alone and it will take 12 days. How many days will it take for Team B to repair the waterway alone?
修一条水道，甲乙两队合作10天可以完成．两队合作4天后，余下的由甲队单独修还需12天．那么乙队单独修这条水道需要多少天．
<gadget id="calculator">1 / 10</gadget>
<output>1/10 = around 0.1</output>

<gadget id="calculator">(1/10) * 4</gadget>
<output>2/5 = around 0.4</output>

<gadget id="calculator">1 - (2/5)</gadget>
<output>3/5 = around 0.6</output>

<gadget id="calculator">(3/5) / 12</gadget>
<output>1/20 = around 0.05</output>

<gadget id="calculator">(1/10) - (1/20)</gadget>
<output>1/20 = around 0.05</output>

<gadget id="calculator">1 / (1/20)</gadget>
<output>20</output>

<result>20</result>