Master Chen went to get off work from 7:30 in the morning to 11:30 in the morning, and repaired 160 chairs in total. How many chairs are repaired per hour on average?
陈师傅上午7：30上班到11：30下班，共修理椅子160张，平均每小时修多少张？
<gadget id="calculator">160 / 4</gadget>
<output>40</output>

<result>40</result>