Question

The number of boys and girls in a class are in the ratio 7:5.If the number of

boys is 8 more than the number of girls. What is the total class strength?​

Answer 1

Answer:

48

Step-by-step explanation:

Let no. of girls be y

and no. of boys became y+8

Ratio is 7:5 ,

$\frac{y+8}{y} =\frac{7}{5}$

By cross multiplying -

$5(y+8)=7y$

⇒$5y+40=7y$

⇒$7y-5y=40$

⇒$2y=40$

⇒$y=20$

No. of girls = 20

No. of boys = y+8 =20+8 = 28

Total Class Strength = 20+28 =48

Answer 2

Given :

• The ratio of gírls and boys - 7:5
• Number of boys more than gírls = 8

To find :

the total class strength

Solution :

• Let the no of boys be 7x and no of gírls be 5x.

⇒ Let's find the total class strength.

7x = 5x + 8

7x - 5x = 8

2x = 8

x = 8/2

= 4

→ No of gírls = 5x

= 5 × 4

= 20 gírls

→ No of boys = 7x

= 7 × 4

= 28 boys

✳ Total Strength = No of boys + No of gírls

= 28 + 20

= 48

• Therefore, the total strength of class is 48.