Question

the ratio of the number of girls to the number of boys in a school of 720 students is 3:5.If 18 new boys were admitted in the school,find how many new girls may be admitted so that the ratio of number of girls to the number of boys may change to 2:3?​

Answer 1

Answer:

42

Step-by-step explanation:

G:B=3:5

3:5= 720

3x:5x=720

3x+5x=720

8x=720

X=720/8

X=90

No. of Girls= 3 x 90=270

No. of Boys= 5 x 90=450

270:450

18 new boys

450+18=468

No. of new girls= a

a+270

New ratio= 2:3

270+a/468=2/3

270+a=468 x 2/3

270+a=312

a=312-270

a=42

42 new girls have been admitted to the school.