A company with 60 people completes a project task in 22 days. After working for 15 days, another 10 people are added. How many days will it take to complete the task?
一个公司60人，用22天的时间完成一项工程的任务，工作15天以后，又增加了10人，还要多少天才能完成任务．
<gadget id="calculator">60 * 22</gadget>
<output>1_320</output>

<gadget id="calculator">60 * 15</gadget>
<output>900</output>

<gadget id="calculator">1_320 - 900</gadget>
<output>420</output>

<gadget id="calculator">60 + 10</gadget>
<output>70</output>

<gadget id="calculator">420 / 70</gadget>
<output>6</output>

<result>6</result>