To produce a batch of products, 40% of this batch of parts is produced in 4 hours. According to this calculation, 120 parts can be produced in 8 hours. How many parts are there in this batch?
生产一批产品，4小时生产了这批零件的40%，照这样计算，8小时可生产120个，这批零件共有多少个？
<gadget id="calculator">120 / 8</gadget>
<output>15</output>

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

<gadget id="calculator">4 / (2/5)</gadget>
<output>10</output>

<gadget id="calculator">15 * 10</gadget>
<output>150</output>

<result>150</result>