Question

a public school in the city have 1170 girls among 2160 students what is the ratio of the boys to girls in the school

Answer 1

no of boys=2160-1170
=990

ratio of boys to girls=990:1170=11:13

hope it helps you....

Answer 2

2160 is the total amount of students which means if you takeaway 1170 (amount of girls) from 2160 you will get amount of boys.

2160–1170=990

Dividing

1170/2160=13/24 (ratio of girls to school)

990/2160=11/24 (ratio of boys to school)

11:13 (ratio of boys to girls)