A project can be completed in 8 hours alone, and B can be completed in 12 hours alone. A can complete the remaining work in 3 hours, and A and B cooperate to complete the remaining work. How many hours will it take?
一项工程，甲单独做8小时完成，乙单独做12小时完成，甲先做3小时，剩下的工作甲乙合作，还需要多少小时可以完成？
<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>