A factory needs to produce 4,500 sets of teaching aids. It is planned to finish it in 15 days, but it actually makes 75 sets more than planned every day. How many days is it actually done?
某工厂要制作4500套教具，计划15天做完，实际每天比计划多做75套，实际几天做完？
<gadget id="calculator">4_500 / 15</gadget>
<output>300</output>

<gadget id="calculator">300 + 75</gadget>
<output>375</output>

<gadget id="calculator">4_500 / 375</gadget>
<output>12</output>

<result>12</result>