Question

Division in a given ratio

In a class of 30 pupils the ratio of the number of boys to the number of girls is 7 : 8. How many girls are there?​

Answer 1

16 girls

Explanation:

sum the parts of the ratio, 7 + 8 = 15 parts

Divide the number of pupils by 15 to find the value of one part of the ratio.

30 ÷ 15 = 2 pupils ← value of 1 part of the ratio, then

8 parts = 8 × 2 = 16 ← number of girls

Answer 2

Explanation:

let the ratio 7:8 be 7x and 8x.

now

7x+8x=30

or, 15x=30

or, x= 30/ 15

or, x= 2

here

no. of boys = 7x= 7*2 = 14

no. of girls= 8x = 8*2= 16

hope this helps u...