According to the statistics of the number of students participating in the school's interest group activities, there are 37 students participating in science and technology activities, 7 more than twice the number of students participating in cultural activities. How many students participate in cultural activities?
据学校兴趣小组活动的人数统计，参加科技活动的同学有37人，比参加文艺活动人数的2倍还多7人．参加文艺活动的同学有多少人？
<gadget id="calculator">37 - 7</gadget>
<output>30</output>

<gadget id="calculator">30 / 2</gadget>
<output>15</output>

<result>15</result>