Students in Class 1 and Class 2 of the third grade go out in 4 cars. There are 45 students in Class 1 and 39 students in Class 2. How many people does each car take on average?
三年级一班和二班的同学乘4辆汽车外出游玩，一班有45人，二班有39人．平均每车坐多少人？
<gadget id="calculator">45 + 39</gadget>
<output>84</output>

<gadget id="calculator">84 / 4</gadget>
<output>21</output>

<result>21</result>