The chorus at an elementary school is made up of fifth and sixth
graders. This year, the chorus has 12 fifth-grade girls, 9 fifth-grade
boys, 14 sixth-grade girls, and 10 sixth-grade boys.
a. The ratio of girls to boys is to .
b. The ratio of fifth graders to sixth graders is : .
c. The ratio of girls to the total number of students in the chorus is □
□