Question

Question :-

The number of boys and girls in a class are in the ratio 7:5. The number of boys is 8 more than the number of girls. What is the total class strength?

Nospam

Answer 1

Answer:

Number of girls is 20 and number of boys is 28.

Step-by-step explanation:

Let the number of girls be 'x'

( The number of boys is 8 more than the number of girls.)

:. Hence, the number of boys is 'x+8'.

Ratio of boys and girls is 7:5.

$\frac{number \: of \: boys}{number \: of \: girls} = \frac{7}{5} \\ \frac{x + 8}{x} = \frac{7}{5} \\ (x + 8) \times 5 = 7 \times x \\ 5x + 40 = 7x$

$40 = 7x - 5x \\ 40 = 2x \\ \frac{40}{2} = x \\ x = 20$

.: Number of girls = x = 20

Number of boys = x+8 = 20 + 8 = 28

Answer 2

✮ Question -:

The number of boys and girls in a class are in the ratio 7:5. The number of boys is 8 more than the number of girls. What is the total class strength?

✮ Explanation -:

Given :

• Ratio of boys and girls = 7 : 5
• Number of boys is 8 more than the number of girls

To Find :

• Total strength of the class

Solution :

Let us assume number of boys as '7x' and number of girls as '5x'

According To Question

$\small\rm \bf{7x = 5x + 8}$

$➩ \: \small\rm{7x - 5x = 8}$

$➩ \: \small\rm{2x = 8}$

$➩ \: \small\rm{x = \frac{8}{2} = 4}$

$\small\boxed{ \pmb{x = 4}}$

Number of boys = 7x

→ 7 × 4

→ 28

Number of boys = 28

Number of girls = 5x

→ 5 × 4

→ 20

Number of girls = 20

Total number of children in the class

= 28 + 20

= 48.

Hence, the strength of the class is 48.