The shoe factory rushes to produce a batch of shoes. It produced 20% of the total number on the first day, and 7/20 of the total number on the second day. A total of 4,400 pairs were produced in two days. How many pairs are there in this batch?
制鞋厂赶制一批鞋子，第一天生产了总数的20%，第二天生产了总数的(7/20)，两天共生产了4400双，这批鞋子一共有多少双？
<gadget id="calculator">20 / 100</gadget>
<output>1/5 = around 0.2</output>

<gadget id="calculator">7 / 20</gadget>
<output>7/20 = around 0.35</output>

<gadget id="calculator">(1/5) + (7/20)</gadget>
<output>11/20 = around 0.55</output>

<gadget id="calculator">4_400 / (11/20)</gadget>
<output>8_000</output>

<result>8_000</result>