Jiasheng Garment Factory received the task of producing a batch of shirts, and produced 450 pieces in the first 3 days, completing 15% of the task. Based on this calculation, how many days will it take to complete this task7? (answer in multiple ways)
佳盛服装厂接到生产一批衬衫的任务，前3天生产了450件，完成了任务的15%，照这样计算，完成这项任务一共需要多少天7？(用多种方法解答)
<gadget id="calculator">15 / 100</gadget>
<output>3/20 = around 0.15</output>

<gadget id="calculator">450 / 3</gadget>
<output>150</output>

<gadget id="calculator">450 / (3/20) / 150</gadget>
<output>20</output>

<result>20</result>