One item, one process, teams A and B cooperate, and it can be completed in 10 days. If Team A does it alone, it will take 15 days to complete. If Team B does it alone, how many days can it be completed?
一项一程，甲乙两队合做，10天可以完成．如果甲队单独做，要15天完成．如果乙队单独做，几天可以完成？
<gadget id="calculator">1 / 10</gadget>
<output>1/10 = around 0.1</output>

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

<gadget id="calculator">(1/10) - (1/15)</gadget>
<output>1/30 = around 0.033333</output>

<gadget id="calculator">1 / (1/30)</gadget>
<output>30</output>

<result>30</result>