A project can be completed in 15 days by A alone, and 10 days by B alone. If A and B cooperate with each other, and B rests for 7 days during the construction period, how many days can it be completed?
一项工程，甲单独做15天完成，乙单独做10天完成，这项工作甲、乙两人合作，并且施工期间乙休息7天，则多少天可完成？
<gadget id="calculator">1 / 10</gadget>
<output>1/10 = around 0.1</output>

<gadget id="calculator">(1/10) * 7</gadget>
<output>7/10 = around 0.7</output>

<gadget id="calculator">(7/10) + 1</gadget>
<output>17/10 = around 1.7</output>

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

<gadget id="calculator">(1/15) + (1/10)</gadget>
<output>1/6 = around 0.166667</output>

<gadget id="calculator">(17/10) / (1/6)</gadget>
<output>51/5 = around 10.2</output>

<result>51/5 = around 10.2</result>