If A and B work together to complete a project in 15 days, if A does it alone, it will take 25 days to complete it, and if B does it alone, how many days will it take to complete it?
一项工程，甲乙合作15天完成，如果由甲单独做需要25天完成，如果由乙单独做需要几天可以完成？
<gadget id="calculator">1 / 15</gadget>
<output>1/15 = around 0.066667</output>

<gadget id="calculator">1 / 25</gadget>
<output>1/25 = around 0.04</output>

<gadget id="calculator">(1/15) - (1/25)</gadget>
<output>2/75 = around 0.026667</output>

<gadget id="calculator">1 / (2/75)</gadget>
<output>75/2 = around 37.5</output>

<result>75/2 = around 37.5</result>