The average marks of boys in a class is 52 and that of girls is 42.

Question

The average marks of boys in a class is 52 and that of girls is 42. The average marks of boys
and girls combined is 50. The percentage of boys in the class is

Accepted Answer

Let x and y are number of boys and girls in a class respectively.

$$\therefore$$ 52x + 42y = 50 (x + y)

$$ \Rightarrow$$ 52x + 42y = 50x + 50y

$$ \Rightarrow$$ 2x = 8y

$$ \Rightarrow$$ x = 4y

$$\therefore$$ Total no. of students = x + y = 4y + y = 5y

$$\therefore$$ Percentage of boys = $${{4y} \over {5y}} \times 100\,\% $$ = 80\%

Solutions · 1