Master Li is used to resting for 2 days every 5 working days. Recently, he received a task to produce 300 parts, and he produces 30 parts a day, so how many days will it take to complete this batch of tasks?
李师傅习惯每工作5天休息2天．最近接到了生产300个零件的任务，他每天生产30个，那么完成这批任务至少需要多少天．
<gadget id="calculator">5 * 1</gadget>
<output>5</output>

<gadget id="calculator">300 / 30 / 5</gadget>
<output>2</output>

<gadget id="calculator">5 + 2 + 5</gadget>
<output>12</output>

<result>12</result>