Question

Urgent please

The ratio of girls to boys in a class of 40 students is 3:5. If 3 new girls joint the class and 1 boy leaves, find the new ratio of girls to boys

Answer 1

Ratio of boys to girls in class

3 : 5 40

Boys + giris 3 + 5 = 8 Total 40

Unit of ratio - 40/8 = 5

Boys = 5 * 3 = 15 Girls = 5 * 5 = 25 Total 40

Add 3 new girls Girls 25 + 3 = 28

Minus 1 boy Boys 15 - 1 = 14

New ratio boys to girls is 14 : 28

Simplify 14/28 = 1/2

New simplified ratio of boys to girls is 1 : 2

Answer 2

Boys : Girls = 3 : 5

3 + 5 = 8 parts

Find 1 part:

8 parts = 40 students

1 part = 40 ÷ 8 = 5 students

Find number of boys and girls:

3 parts = 3 x 5 = 15 girls

5 parts = 5 x 5 = 25 boys

Original Number of students = 15 : 25

Find new ratio:

New Ratio = 15 + 3 : 25 - 1 = 18 : 24 = 3 : 4

Answer: 3 : 4