A factory plans to produce 400 parts per day, and it will take 30 days to complete. In fact, 3,000 parts were produced in the first 6 days. According to this calculation, how many days will it take to complete the original plan? (Respectively use positive and negative proportional solution)
某工厂计划每天生产400个零件，要30天完成，实际上前6天就产生了3000个，照这样计算，完成原计划任务要多少天？(分别用正、反比例解)
<gadget id="calculator">400 * 30</gadget>
<output>12_000</output>

<gadget id="calculator">3_000 / 6</gadget>
<output>500</output>

<gadget id="calculator">12_000 / 500</gadget>
<output>24</output>

<result>24</result>