One job, A and B work together, the whole project can be completed every day (9/80), team A can complete the whole project after 3 days alone, and team B can complete the whole project after 6 days alone (7/16). How many days will it take for the entire project to be completed by Team B alone? (Hint: Think of A and B working together for three days, and B doing it alone for three days)
一件工作，甲乙合做，每天能完成全工程的(9/80)，甲队独做3天，乙队独做6天后，可以完成全工程的(7/16)．全工程由乙队独做需多少天完成？(提示：看作甲乙合做三天后，乙独做三天)
<gadget id="calculator">7 / 16</gadget>
<output>7/16 = around 0.4375</output>

<gadget id="calculator">9 / 80</gadget>
<output>9/80 = around 0.1125</output>

<gadget id="calculator">(9/80) * 3</gadget>
<output>27/80 = around 0.3375</output>

<gadget id="calculator">(7/16) - (27/80)</gadget>
<output>1/10 = around 0.1</output>

<gadget id="calculator">6 - 3</gadget>
<output>3</output>

<gadget id="calculator">(1/10) / 3</gadget>
<output>1/30 = around 0.033333</output>

<gadget id="calculator">1 / (1/30)</gadget>
<output>30</output>

<result>30</result>