For a batch of clothes, 15% of the total number of pieces were processed on the first day, and 18% of the total number of pieces were processed on the second day. The second day processed 90 more pieces than the first day. How many pieces of clothing are there in this batch?
一批衣服，第一天加工了总件数的15%，第二天加工了总件数的18%．第二天比第一天多加工90件．这批衣服有多少件？
<gadget id="calculator">18 / 100</gadget>
<output>9/50 = around 0.18</output>

<gadget id="calculator">15 / 100</gadget>
<output>3/20 = around 0.15</output>

<gadget id="calculator">(9/50) - (3/20)</gadget>
<output>3/100 = around 0.03</output>

<gadget id="calculator">90 / (3/100)</gadget>
<output>3_000</output>

<result>3_000</result>