If the ratio of girls to boys is 3:5, that means that for every 8 total students, 3 would be girls and 5 would be boys. Therefore 3/8 of the students are girls and 5/8 are boys. If 3/8 are girls, then:
.72 divided by 6 is 12. So they make 12 cents per ticket, so that means you would have to do 12 times 11 and that should get you 132 cents and that is equivalent to $1.32.