One piece of project A can be completed in 8 days alone. After this project B works alone for 3 days, A works alone for 4 days to complete the remaining work. How many days will it take for B to complete this project alone?
一件工程甲单独做8天完成．这件工程乙单独做3天后，剩下的甲又单独做4天完成．这件工程乙单独做要多少天完成？
<gadget id="calculator">1 / 8</gadget>
<output>1/8 = around 0.125</output>

<gadget id="calculator">(1/8) * 4</gadget>
<output>1/2 = around 0.5</output>

<gadget id="calculator">1 - (1/2)</gadget>
<output>1/2 = around 0.5</output>

<gadget id="calculator">(1/2) / 3</gadget>
<output>1/6 = around 0.166667</output>

<gadget id="calculator">1 / (1/6)</gadget>
<output>6</output>

<result>6</result>