For a project, two teams, A and B, can complete the entire project every day (9/40), and A can complete the whole project after 3 days and B alone for 5 days (7/8). If the whole process is done by Team B alone. How many days can it be done?
一项工程，甲乙两队合作每天能完成全工程的(9/40)，甲独做3天，乙独做5天后，可完成全程的(7/8)．如果全程由乙队独做．多少天可以完成？
<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>