On the first day, the store sold 250 shirts in the morning, 20 in the afternoon, and 320 in the second day. What is the average number of shirts sold per day?
商店第一天上午卖出衬衫250件，下午卖出20件，第二天共卖出320件，平均每天卖出多少件．
<gadget id="calculator">250 + 20 + 320</gadget>
<output>590</output>

<gadget id="calculator">590 / 2</gadget>
<output>295</output>

<result>295</result>