It takes 20 days to complete a job B alone. Now, A and B will do it together for 5 days, and B will do it alone for 3 days, and there are still (2/5) unfinished. How many days will it take if A alone completes this job?
一项工作乙独做需要20天完成，现在先由甲乙合做5天，乙再独做3天后，还有(2/5)没有完成，如果这项工作由甲单独完成需要多少天？
<gadget id="calculator">2 / 5</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">1 / 20</gadget>
<output>1/20 = around 0.05</output>

<gadget id="calculator">5 + 3</gadget>
<output>8</output>

<gadget id="calculator">(1/20) * 8</gadget>
<output>2/5 = around 0.4</output>

<gadget id="calculator">(3/5) - (2/5)</gadget>
<output>1/5 = around 0.2</output>

<gadget id="calculator">(1/5) / 5</gadget>
<output>1/25 = around 0.04</output>

<gadget id="calculator">1 / (1/25)</gadget>
<output>25</output>

<result>25</result>