The People’s Machinery Factory processes a batch of parts. Workshop A processes 20% of this batch of parts, Workshop B processes the remaining 25%, and Workshop C processes the remaining 40%. There are still 3,600 unprocessed parts. How many parts are there in this batch?
人民机械厂加工一批零件，甲车间加工这批零件的20%，乙车间加工余下的25%，丙车间加工再余下的40%，还剩下3600个没加工，这批零件共有多少个？
<gadget id="calculator">20 / 100</gadget>
<output>1/5 = around 0.2</output>

<gadget id="calculator">1 - (1/5)</gadget>
<output>4/5 = around 0.8</output>

<gadget id="calculator">25 / 100</gadget>
<output>1/4 = around 0.25</output>

<gadget id="calculator">(4/5) * (1/4)</gadget>
<output>1/5 = around 0.2</output>

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

<gadget id="calculator">40 / 100</gadget>
<output>2/5 = around 0.4</output>

<gadget id="calculator">(3/5) * (2/5)</gadget>
<output>6/25 = around 0.24</output>

<gadget id="calculator">1 - (1/5) - (1/5) - (6/25)</gadget>
<output>9/25 = around 0.36</output>

<gadget id="calculator">3_600 / (9/25)</gadget>
<output>10_000</output>

<result>10_000</result>