Yunxian Garment Factory received the task of producing 1,200 shirts, and 40% of them were completed in the first 3 days. Based on this calculation, how many days will it take to complete the production task?
郧县服装厂接到生产1200件衬衫的任务，前3天完成了40%，照这样计算，完成生产任务还要多少天？
<gadget id="calculator">40 / 100</gadget>
<output>2/5 = around 0.4</output>

<gadget id="calculator">1 - (2/5)</gadget>
<output>3/5 = around 0.6</output>

<gadget id="calculator">(2/5) / 3</gadget>
<output>2/15 = around 0.133333</output>

<gadget id="calculator">1_200 * (2/15)</gadget>
<output>160</output>

<gadget id="calculator">(3/5) / 160</gadget>
<output>3/800 = around 0.00375</output>

<gadget id="calculator">1_200 * (3/800)</gadget>
<output>9/2 = around 4.5</output>

<result>9/2 = around 4.5</result>