A project can be completed by A alone in 10 days and B by himself in 12 days. After A and B work together for 3 days, A will do the rest alone. How many days will it take to complete?
一项工程，甲独做10天完成，乙独做12天完成．甲乙合做3天后，剩下的由甲独做，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) * 3</gadget>
<output>11/20 = around 0.55</output>

<gadget id="calculator">1 - (11/20)</gadget>
<output>9/20 = around 0.45</output>

<gadget id="calculator">(9/20) / (1/10)</gadget>
<output>9/2 = around 4.5</output>

<result>9/2 = around 4.5</result>