The answer is C. 423.52 m
draw the lines down all the ways that it is equal on each side
Class ratio of girls to boys is 3:5
So there are 3 girls and 5 boys in 8 students
If there are 32 students, then 3/(3+5) * 32 = 12 girls, and 5/(3+5) * 32 = 20 boys
Hope it helps you?