On the first day, the store sold 25 shirts in the morning, 21 in the afternoon, and 32 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25件，下午卖出21件，第二天共卖出32件，平均每天卖出多少件．
<gadget id="calculator">25 + 21 + 32</gadget>
<output>78</output>

<gadget id="calculator">78 / 2</gadget>
<output>39</output>

<result>39</result>