A project is completed in 6 days by teams A and B. If A works alone in 15 days, how many days will it take for B to complete it alone?
一项工程，甲乙两队6天完成，如果甲单独做15天完成，那么乙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>