Xinhua Bookstore sold a total of 129 books from 8:00 to 11:00, and the average number of books sold per hour.
新华书店从8：00--11：00一共买出129本书，平均每小时买出多少本书．
<gadget id="calculator">11 - 8</gadget>
<output>3</output>

<gadget id="calculator">129 / 3</gadget>
<output>43</output>

<result>43</result>