A project can be completed by team A alone in 5 days, but team B can only complete (2/3) of the project in the same time. How many days will it take for the two teams to work together to complete the project?
一项工程，甲队单独做5天完成，乙队在相同的时间内只完成了这项工程的(2/3)．两队合作几天能完成这项工程？
<gadget id="calculator">1 / 5</gadget>
<output>1/5 = around 0.2</output>

<gadget id="calculator">2 / 3</gadget>
<output>2/3 = around 0.666667</output>

<gadget id="calculator">(1/5) * (2/3)</gadget>
<output>2/15 = around 0.133333</output>

<gadget id="calculator">(1/5) + (2/15)</gadget>
<output>1/3 = around 0.333333</output>

<gadget id="calculator">1 / (1/3)</gadget>
<output>3</output>

<result>3</result>