Final answer:
To find the number of girls in the group, set up a system of equations based on the given information. Solve the equation to find the number of girls is 120.
Step-by-step explanation:
To find the number of girls in the group, we can set up a system of equations based on the given information. Let x represent the number of girls in the group. According to the ratio, the number of boys is 5/3 times the number of girls. So the number of boys is (5/3)x. We are also given that there are 80 more boys than girls, so (5/3)x - x = 80. Simplifying this equation, we get (2/3)x = 80. Multiplying both sides by 3/2, we find x = 120. Therefore, there are 120 girls in the group.