A project alone takes 8 days to complete, and B alone takes 12 days to complete. If A works for 3 days first, and then the two teams work together, how many days will it take to complete?
一项工程，甲单独要8天完成，乙单独做要12天完成．如果甲先做3天后，再由两队合做，还要几天完成？
<gadget id="calculator">1 / 8</gadget>
<output>1/8 = around 0.125</output>

<gadget id="calculator">(1/8) * 3</gadget>
<output>3/8 = around 0.375</output>

<gadget id="calculator">1 - (3/8)</gadget>
<output>5/8 = around 0.625</output>

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

<gadget id="calculator">(1/8) + (1/12)</gadget>
<output>5/24 = around 0.208333</output>

<gadget id="calculator">(5/8) / (5/24)</gadget>
<output>3</output>

<result>3</result>