project, A and B work together, can complete the whole project every day (9/40), after A and B work together for 3 days, B team can complete the whole project for another 2 days (7/8) ． How many days will it take for the entire project to be completed by Team B alone?
一项工程，甲、乙合做，每天能完成全工程的(9/40)，甲、乙两队合做3天后，乙队再独做2天，可以完成全工程的(7/8)．全工程由乙队独做需多少天完成？
<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">(1/5) / 2</gadget>
<output>1/10 = around 0.1</output>

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

<result>10</result>