A garment factory wants to process a batch of skirts. It processed 120 sets in the first 4 days and 150 sets in the next 5 days. How many sets are processed on average per day?
某服装厂要加工一批套裙，前4天加工了120套，后5天加工了150套正好完成，平均每天加工多少套？
<gadget id="calculator">120 + 150</gadget>
<output>270</output>

<gadget id="calculator">4 + 5</gadget>
<output>9</output>

<gadget id="calculator">270 / 9</gadget>
<output>30</output>

<result>30</result>