There are 120 students in the fifth grade, and the ratio of boys to girls is 7:5. How many girls are there?
五年级有120人，男、女生人数比是7：5，女生有多少人．
<gadget id="calculator">7 + 5</gadget>
<output>12</output>

<gadget id="calculator">5 / 12</gadget>
<output>5/12 = around 0.416667</output>

<gadget id="calculator">120 * (5/12)</gadget>
<output>50</output>

<result>50</result>