It takes 6 days for two teams to complete a project together, and 15 days for team A to complete it alone. What is the work efficiency of team B?
两队合作完成一项工程需要6天，甲队单独完成需要15天，乙队的工作效率是多少．
<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>

<result>1/10 = around 0.1</result>