Question

the ratio of number of boys and girls in a school 7:8 if the number of in a school is 2400 find the percentage of boys in school and number of girl ?​

Answer 1

Answer:

The Number of girls are 1280 and boys are 46.66 % (approx).

Step-by-step explanation:

Given :

Ratio of boys to girls = 7 : 8

Total students = 2400

To find :

Percentage of boys and number of girls

Solution :

Let the -

• Number of boys be 7x
• Number of girls be 8x

⇒ 7x + 8x = 2400

⇒ 15x = 2400

⇒ x = 2400/15

⇒ x = 160

$\rule{300}{1.5}$

★ Value of 7x

⇒ 7(160)

⇒ 1120

Boys = 1120

$\rule{300}{1.5}$

★ Value of 8x

⇒ 8(160)

⇒ 1280

Girls = 1280

$\rule{300}{1.5}$

★ Percentage of Boys -

⇒ $\sf{\dfrac{1120}{2400} \times 100}$

⇒ $\sf{ \dfrac{112000}{2400}}$

⇒ $\sf{46.66\%}$

Percentage of the boys = 46.66 % (approx)

$\therefore$ The Number of girls are 1280 and boys are 46.66 % (approx).

Answer 2

Given : Total no. of students in school = 2400

Ratio of boys and girls = 7 : 8

To find: The percentage of boys in school and the number of girls

Solution : Let the ratio be 7x: 8x

$\therefore \: total \: ratio \: = 7x + 8x = 15x$

So,

The number of girls

$\dfrac{8 { \cancel{x}}}{ \cancel{15 }{ \cancel{x}}} \times { \cancel{2400}}$

$\implies \: 8 \times 160$

$\implies \: 1280$

Therefore the number of girls = 1280

____________________________________________

Now,

The no of boys = Total no of students - total no of girls

=> No of boys = 2400 - 1280

=> No of boys = 1120

_________________________________________

$The \: percentage \: of \: boys \: = \dfrac{no \: of \: boys}{total \: no \: of \: students} \times 100$

$\implies \: \dfrac{1120}{2400} \times 100 \\ \\ \implies \: \frac{112000}{2400}$

$\implies \: 46.66\%$

Therefore the percentage of boys = 46.66 percent