A project, A and B work together to complete the project every day (9/40), if A first works for 3 days, and then B works alone for 5 days to complete the project (7/8), B alone does this How many days will the project be completed?
一项工程，甲、乙二人合作每天完成工程的(9/40)，如果甲先做3天，接着乙独做5天共完成这项工程的(7/8)，乙独做这项工程要多少天完成？
<gadget id="calculator">7 / 8</gadget>
<output>7/8 = around 0.875</output>

<gadget id="calculator">9 / 40</gadget>
<output>9/40 = around 0.225</output>

<gadget id="calculator">(9/40) * 3</gadget>
<output>27/40 = around 0.675</output>

<gadget id="calculator">(7/8) - (27/40)</gadget>
<output>1/5 = around 0.2</output>

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

<gadget id="calculator">(1/5) / 2</gadget>
<output>1/10 = around 0.1</output>

<gadget id="calculator">1 / (1/10)</gadget>
<output>10</output>

<result>10</result>