A project can be completed in 10 days by team A alone, 15 days by team B alone, and 3 days by the two teams. If only one team is assigned to complete the rest of the project, how many days will it take at least?
一项工程，甲队独做10天完成，乙队独做15天完成，两队合做3天，只安排一个队完成剩下的工程，至少还需多少天？
<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">(1/6) * 3</gadget>
<output>1/2 = around 0.5</output>

<gadget id="calculator">1 - (1/2)</gadget>
<output>1/2 = around 0.5</output>

<gadget id="calculator">(1/2) / (1/10)</gadget>
<output>5</output>

<result>5</result>