Question

The ratio of the number of boys and girls in a school is 4:5, if there are 630 students in the school. find the number of boys? a. 280 b. 200 c. 300 Od. 400​

Answer 1

Given :

• Ratio of the number of boys and girls in a school = 4:5
• Total students in a school = 630

To Find :

• Number of boys?

Solution :

$\longmapsto\:\tt Let\:number\:of\:boys = \bf{4x}$

$\longmapsto\:\tt Let\:number\:of\:boys = \bf{5x}$

According to the Question :

• Total number of students in a school is 630. Hence,

$\longmapsto\:\tt Number_{(Boys\:+\:Girls)} = 630$

$\longmapsto\:\tt 4x + 5x = 630$

$\longmapsto\:\tt 9x = 630$

$\longmapsto\:\tt x = {\cancel{\dfrac{630}{9}}}$

$\purple{\longmapsto}\:{\large{\underline{\boxed{\bf{\blue{x} \pink{=} \red{70}}}}}}$

Therefore :

$\longmapsto\:\tt Number\:of\:boys = 4(70)$

$\longmapsto\:\bf 280$

Hence, number of boys is 280.

━━━━━━━━━━━━━━━

$\longmapsto\:\tt Number\:of\:girls = 5(70)$

$\longmapsto\:\bf 350$

Verification :

• Total number of students in a school is 630. Hence,

$\longmapsto\:\tt Number_{(Boys\:+\:Girls)} = 630$

$\longmapsto\:\tt 4x + 5x = 630$

$\longmapsto\:\tt 9x = 630$

$\longmapsto\:\tt 9(70) = 630$

$\longmapsto\:\tt 630 = 630$

$\longmapsto\:\bf LHS = RHS$

Hence, Verified.

Learn More :

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?

Answer :

• brainly.in/question/44410107

━━━━━━━━━━━━━━━

Answer 2

Answer:

• Option A. 280

Step-by-step explanation:

Given,

• The ratio of the number of boys and girls in a school is 4 : 5.
• There are 630 students in the school.

To Find,

• The number of boys.

Solution,

Let's,

• The number of boys = 4x

So,

• The number of girls = 5x

According To Question,

Total number of Students = 630

• ➤ 4x + 5x = 630
• ➤ 9x = 630
• ➤ x = 70

The value of x is 70.

The number of boys = 4x

• The number of boys = 280

The number of girls = 5x

• The number of girls = 350

Required Answer,

• The number of boys = 280