Question

Ratio between the girls and boys in class of 40 students is 2:3. Five students joinded the class. How many of them must be boys so that the ratio between girls and boys becomes 4:5?

Answer 1

THE NUMBERS OF BOYS STUDENT JOIN IS  1

STEP BY STEP EXPLANATION:

* Let the no of boy be : 3x

 * Let the no of girl be : 2x

A/Q

     2x +3x =40

         5x=40

             x=8

  GIRLS = 2x=2

 BOYS =3x=3×8=24

When 5 student join the classes:

 Rotio become 4:5

Therefore  let no of boys be: 5y

                  Let the no girls be :4y

A/Q

     5y + 4y=40+5

         9y=45

        Y =5

Yherefore now no of boys are= 5y

                                                  =5×5=25

   

   Therefore  no boys joined= 25-24 =1

  THEREFORE THE NO OPF BOYS STUDENT JOIN THE CLASS IS 1