Question

The number of students in a class is 60. The number of boys is seven-fifths of the number of girls. Find the number of boys in the class.

Answer 1

Let the number of girls be x

So, the number of boys be 7x/5

According to Question,

Given : Total number of students = 60

x + 7x / 5 = 60

⇨ (5x + 7x) / 5 = 60

⇨ 12x = 300

⇨ x = 300 / 12

⇨ x = 25

Required number of students -

Girls = x = 25

Boys = 7x/5 = 7(25)/5 = 175/5 = 35

Hence, the number of boys is 35 and the number of girls is 25

Answer 2

Let the number of girls = x

number of boys = 7x/5

Given : Total students = 60


$x + \dfrac{7x}{5} = 60$



$\dfrac{5x + 7x}{5} = 60$


$\dfrac{12x}{5} = 60$


$12x = 60 \times 5$


$x = \dfrac{300}{12} = 25$

$x = 25$


Hence :

$number \: of \: girls \: (x) = 25$


$number \: of \: boys = \dfrac{7x}{5} \\ \\ = \dfrac{7(25)}{5} = \dfrac{175}{5} = 35$

$\bold{Number \: of \: boys \: = \: 35}$