A project will be completed in 10 days by A alone, and 12 days by B alone. After 2 days of joint work by A and B, A leaves for something, and B will do the rest alone. How many days will it take to complete?
一项工程，甲单独做要10天完成，乙单独做要12天完成，甲、乙合做2天后，甲有事离开，剩下的由乙单独做，还要几天完成？
<gadget id="calculator">1 / 10</gadget>
<output>1/10 = around 0.1</output>

<gadget id="calculator">1 / 12</gadget>
<output>1/12 = around 0.083333</output>

<gadget id="calculator">(1/10) + (1/12)</gadget>
<output>11/60 = around 0.183333</output>

<gadget id="calculator">(11/60) * 2</gadget>
<output>11/30 = around 0.366667</output>

<gadget id="calculator">1 - (11/30)</gadget>
<output>19/30 = around 0.633333</output>

<gadget id="calculator">(19/30) / (1/12)</gadget>
<output>38/5 = around 7.6</output>

<result>38/5 = around 7.6</result>