Question

In a school there are 420 boys and 180 girls find the ratio of girls to boys girls to total number of students and boys 2 total number of students

Answer 1

girls to boys,

180 /420 => 9/21 => 3/7

therefore, 3:7

total - 600

girls to total

=180/600

=9/30

3:10 ratio

boys to total

=420/600

=21/30

= 7/10

therefore, 7:10 ratio

Answer 2

Given: Number of boys in the school = 420

           Number of girls in the school = 180

To find: (i) Ratio of girls to boys

            (ii) Ratio of girls to total number of students

           (iii) Ratio of boys to total number of students

Solution: According to the given question,

Total number of students in the school = Number of boys + Number of girls

                                                                 = 420 + 180

                                                                 = 600

(i) Ratio of girls to boys = $\frac{Number \ of \ girls}{Number \ of \ boys}$

                                      = $\frac{180}{420}$ = $\frac{3}{7}$ $or \ 3 : 7$

(ii) Ratio of girls to total number of students = $\frac{Number \ of \ girls}{Total \ number \ of \ students}$

                                                                        = $\frac{180}{600} = \frac{3}{10} \ or \ 3 : 10$

(iii) Ratio of boys to total number of students = $\frac{Number \ of \ boys}{Total \ number \ of \ students}$

                                                                          = $\frac{420}{600} = \frac{7}{10} \ or \ 7 : 10$

Hence, ratio of girls to boys is 3 : 7, girls to total number of students is 3 : 10 and boys to total number of students is 7 : 10.