There are 7 classes in the sixth grade of Linhu Primary School, with an average of 40 students in each class. The ratio of boys to girls in the sixth grade is 4:3. How many girls are there in the sixth grade of Linhu Primary School?
临湖小学六年级7个班，平均每个班有40名学生，六年级男生和女生人数的比是4：3，临湖小学六年级共有女生多少人？
<gadget id="calculator">4 + 3</gadget>
<output>7</output>

<gadget id="calculator">3 / 7</gadget>
<output>3/7 = around 0.428571</output>

<gadget id="calculator">40 * 7 * (3/7)</gadget>
<output>120</output>

<result>120</result>