Question

In a class of $35$ students, the number of girls is two-fifth of the number of boys. Find the number of girls in the class.

Answer 1

Let the number of girls = $g$

let the number of boys= $b$

Total no. of the students in the class= $35$ (given)

so,

$g+b=35$ ........(1)

The number of girls is two-fifth of the number of boys.

So,

$g=\frac{2}{5}b$ ..... (2)

From (1) and (2),

$\frac{2}{5}b+b=35$

$\frac{7}{5}b=35$

$b=\frac{35\times 5}{7}$

$b=25$

now, from (1),

$g+25=35$

$g=35-25=10$

Therefore, the no. of girls in the class is $10$