Question

the ratio of boys and girls is 2:5 if there are 280 students find the number of girls in the school​

Answer 1

Answer:

40

Step-by-step explanation:

let number of boys and girls be 2x and 5x respectively.

ATQ,

2x+5x=280

7x=280

x=280/7

x=40

Answer 2

Given :

• Ratio of boys and girls is 2 : 5

• Total number of students = 280

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To find :

• Number of girls in the school

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Assumption :

Let the common term in the ratio be x

Therefore -

• Number of boys = 2x

• Number of girls = 5x

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Solution :

According to the question -

The total number of students = 280

$\sf\implies\:Number~of~boys~+~Number~of~girls~=~280$

Substituting the values

$\sf:\implies\:2x~+~5x~=~280$

Adding the like terms

$\sf:\implies\:7x~=~280$

Transposing 7 to RHS it goes to the denominator

$\sf:\implies\:x~=~\frac{280}{7}$

Reducing the fraction to lower terms

$\sf:\implies\:x~=~\cancel{\frac{280}{7}}$

$\small{\underline{\boxed{\mathrm{:\implies~x~=~40}}}}$ ★

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Now :

• The number of boys = 2x = 2 × 40 = $\small\fbox{80}$

• The number of girls = 5x = 5 × 40 = $\small\fbox{200}$

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Verification :

In total the number of students is 280 .

$\tt\:Number~of~boys~+~Number~of~girls~=~280$

$\tt\leadsto\:80+200=280$

$\tt\leadsto\:280=280$

$\bf\leadsto\:LHS=RHS$

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Henceforth :

❒ Required number of girls = $\large{\mathfrak\red{200}}$

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