For a project, it will take 6 days for teams A and B to complete it together, 15 days for team A to complete it alone, and how many days will it take for team B to complete it alone.
一件工程，甲乙两队合做要6天完成，甲队单独做要15天完成，乙队单独做要多少天完成．
<gadget id="calculator">1 / 6</gadget>
<output>1/6 = around 0.166667</output>

<gadget id="calculator">1 / 15</gadget>
<output>1/15 = around 0.066667</output>

<gadget id="calculator">(1/6) - (1/15)</gadget>
<output>1/10 = around 0.1</output>

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

<result>10</result>