A processing group plans to process a batch of parts. If 20 pieces are processed every day, it can be completed in 15 days. Actual processing 25 per day. According to this calculation, how many days can the task be completed? (Solve with ratio)
某加工小组计划加工一批零件．如果每天加工20个，15天可以完成．实际每天加工25个．照这样计算，几天可完成任务？(用比例解)
<gadget id="calculator">20 * 15</gadget>
<output>300</output>

<gadget id="calculator">300 / 25</gadget>
<output>12</output>

<result>12</result>