job is completed by A and B in cooperation for 12 days. Now A will do it alone for 2 days, and then B will do it for 5 days. The two of them have completed (1/4) of the project. If this project is done by B alone How many days will it take to complete?
一项工作，甲乙两人合作12天完成，现在先由甲独做2天，再由乙独做5天，两人完成了这项工程的(1/4)，假如这项工程由乙单独完成，共需多少天？
<gadget id="calculator">1 / 4</gadget>
<output>1/4 = around 0.25</output>

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

<gadget id="calculator">(1/12) * 2</gadget>
<output>1/6 = around 0.166667</output>

<gadget id="calculator">(1/4) - (1/6)</gadget>
<output>1/12 = around 0.083333</output>

<gadget id="calculator">5 - 2</gadget>
<output>3</output>

<gadget id="calculator">(1/12) / 3</gadget>
<output>1/36 = around 0.027778</output>

<gadget id="calculator">1 / (1/36)</gadget>
<output>36</output>

<result>36</result>