There are 48 students in class 31. After 12 students leave, the rest are arranged in 4 rows. How many students are there on average in each row?
三1班有48名同学，走了12个后，剩下的排成4行，平均每行有多少个同学．
<gadget id="calculator">48 - 12</gadget>
<output>36</output>

<gadget id="calculator">36 / 4</gadget>
<output>9</output>

<result>9</result>