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

The average marks of boys in 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

  1. 20
  2. 40
  3. 60
  4. 80

Answer

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

(52x + 42y)/(x + y) = 50

x = 4y

x/y = 4/1

x/(x+y) = 4/5

So, required percentage = 80%

The correct option is D.