A factory plans to produce a batch of parts in April (30 days), and an average of 400 parts per day is required to complete the task. In fact, 3000 parts were produced in the first 6 days. According to this calculation, how many days will it take to complete the original planned task? (Respectively use positive and negative proportional solution)
某工厂四月份(30天)计划生产一批零件，平均每天要生产400个才能完成任务，实际上前6天就生产了3000个．照这样计算，完成原计划任务要用多少天？(分别用正、反比例解)
<gadget id="calculator">30 * 400</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>