Our county strives to create a "green industry and trade city". In the publicity activities, the ratio of the number of people in the fifth and sixth grades of our school participating in the activity is 3:4, 120 people in the sixth grade, how many people in the fifth grade participated.
我县努力创建"绿色工贸城市"，在宣传活动中，我校五、六年级参加活动的人数比是3：4，六年级的120人，五年级有多少人参加．
<gadget id="calculator">120 / 4</gadget>
<output>30</output>

<gadget id="calculator">30 * 3</gadget>
<output>90</output>

<result>90</result>