After the 5.12 Wenchuan earthquake, a company received the task of producing a batch of prefabricated houses to support the disaster area. After producing 40,000 sets of prefabricated houses, the superior asked to speed up and complete them as soon as possible. Because the company took some measures, the workers' motivation increased greatly , the work efficiency increased by 25%, and the task was completed 2 days ahead of schedule. If the work efficiency was increased by 20% from the beginning, the task could be completed 3 days in advance. How many sets of production tasks are there for this batch of prefab houses?
5.12汶川地震发生后，某公司接到生产一批板房支援灾区的任务，当生产出4万套板房后，上级要求加快速度，尽快提前完成，由于公司采取一些措施，工人们干劲大增，工作效率提高了25%，结果提前2天完成了任务，如果从一开始就把工作效率提高20%，就能提前3天完成任务，问这批板房的生产任务共有多少套？
<gadget id="calculator">15 + 3</gadget>
<output>18</output>

<gadget id="calculator">5_000 * 18</gadget>
<output>90_000</output>

<result>90_000</result>