The municipal greening team has to complete a greening task. Team A can complete it in 10 weeks alone, and team B can complete it in 15 weeks alone. How many weeks can the two teams complete at the same time?
市政绿化队要完成一项绿化任务，甲队单独做10周完成，乙队单独做15周完成，两队同时做几周可以完成？
<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>1/6 = around 0.166667</output>

<gadget id="calculator">1 / (1/6)</gadget>
<output>6</output>

<result>6</result>