Question

The number of boys and girls in a class is in the ratio 9: 5. The
number of boys is 12 more than the number of girls. What is the
total strength of the class.​

Answer 1

Step-by-step explanation:

Let no of girls be x.

So no of boys be X+12.

ATQ,x+12/X=9/5

or 5x+60=9x

or 4x=60

or X=15

no of girls=15 and no of boys=27

Answer 2

The number of boys and girls are in the ratio 9:5.

Let number of boys be 9M and number of girls be 5M.

The number of boys is 12 more than the number of girls.

Number of boys is 9M and number of girls is 5M. And girls are 12 more than that of boys.

According to question,

$\implies\:9M\:=\:5M\:+\:12$

$\implies\:9M\:-\:5M\:=\:12$

$\implies\:4M\:=\:12$

$\implies\:M\:=\:\dfrac{12}{4}$

$\implies\:M\:=\:3$

So,

Number of boys = 9M

= 9(3)

= 27

Number of girls = 5M

= 5(3)

= 15

Now,

We have to tell the total number of strength in the class.

Total stength = Number of boys + Number of girls

$\Rightarrow\:27\:+\:15$

$\Rightarrow\:42$

∴ Total strength of the class is 42.