A project can be completed by two teams working together in 6 days. It is known how many days Team A will complete in 10 days.
一项工程，两队合修6天可以完成，已知甲队修10天完成，乙队要修多少天．
<gadget id="calculator">1 / 6</gadget>
<output>1/6 = around 0.166667</output>

<gadget id="calculator">1 / 10</gadget>
<output>1/10 = around 0.1</output>

<gadget id="calculator">(1/6) - (1/10)</gadget>
<output>1/15 = around 0.066667</output>

<gadget id="calculator">1 / (1/15)</gadget>
<output>15</output>

<result>15</result>