The ratio of the number of boys and girls in the chorus group is 7:5, and there are 25 girls among them. How many boys are there in this chorus group?
合唱组男女生人数的比是7：5，其中有女生25人，这个合唱组男生多少人．
<gadget id="calculator">25 / 5</gadget>
<output>5</output>

<gadget id="calculator">5 * 7</gadget>
<output>35</output>

<result>35</result>