If A alone takes 10 days to complete a job, and if B alone takes 15 days, if A alone does 2 days first, and A and B jointly do the rest, how many days will it take to complete?
一件工作，如果甲单独完成需要10天，如果乙单独完成需15天，如果甲单独先做2天，剩下的由甲乙合做，还需多少天才能完成？
<gadget id="calculator">1 / 10</gadget>
<output>1/10 = around 0.1</output>

<gadget id="calculator">(1/10) * 2</gadget>
<output>1/5 = around 0.2</output>

<gadget id="calculator">1 - (1/5)</gadget>
<output>4/5 = around 0.8</output>

<gadget id="calculator">1 / 15</gadget>
<output>1/15 = around 0.066667</output>

<gadget id="calculator">(1/10) + (1/15)</gadget>
<output>1/6 = around 0.166667</output>

<gadget id="calculator">(4/5) / (1/6)</gadget>
<output>24/5 = around 4.8</output>

<result>24/5 = around 4.8</result>