Maple Leaf Garment Factory received the task of producing 2400 shirts. 40% completed in the first 6 days. According to this calculation, how many days will it take to complete this production task?
枫叶服装厂接到生产2400件衬衫的任务．前6天完成了40%．照这样计算，完成这项生产任务一共要用多少天？
<gadget id="calculator">40 / 100</gadget>
<output>2/5 = around 0.4</output>

<gadget id="calculator">6 / (2/5)</gadget>
<output>15</output>

<result>15</result>