A project can be completed in 24 days by A alone. If A works alone in 6 days, B will do the rest of the work, and B can finish it in 9 days. How many days will it take B to complete the work alone?
一项工程，甲单独做24天可以完成，如果甲单独做6天，余下的工作由乙去做，乙再用9天可以做完．乙单独完成此项工作需要多少天．
<gadget id="calculator">1 / 24</gadget>
<output>1/24 = around 0.041667</output>

<gadget id="calculator">6 * (1/24)</gadget>
<output>1/4 = around 0.25</output>

<gadget id="calculator">1 - (1/4)</gadget>
<output>3/4 = around 0.75</output>

<gadget id="calculator">(3/4) / 9</gadget>
<output>1/12 = around 0.083333</output>

<gadget id="calculator">1 / (1/12)</gadget>
<output>12</output>

<result>12</result>