The students actively participated in interest group activities. There were 17 people participating in the art group, 7 people less than twice the number of people participating in the calligraphy group. How many people participated in the calligraphy group? (solution by equation)
同学们积极参加兴趣小组活动，参加美术组的有17人，比参加书法组人数的2倍少7人，参加书法组的有多少人？(用方程解)
<gadget id="calculator">17 + 7</gadget>
<output>24</output>

<gadget id="calculator">24 / 2</gadget>
<output>12</output>

<result>12</result>