In the third grade, there are 4 classes of students participating in the rope skipping competition. There are 120 students in total. Each class is divided into 2 groups. How many people are there on average in each group?
三年级有4个班的同学参加跳绳比赛，一共有120人，每班分成2组，平均每组有多少人？
<gadget id="calculator">4 * 2</gadget>
<output>8</output>

<gadget id="calculator">120 / 8</gadget>
<output>15</output>

<result>15</result>