Question

A class has x boys and y girls.In an exam ,the average score for the boys is 63 and the average score for the girls is 70.The average for the whole class is 68 . Find x and y .

Answer 1

Sum of scores of boys = 63x.

Sum of scores of girls = 70y.

The average score of all the students:

(63x + 70y)/(x + y) = 68

63x + 70y = 68( x + y)

63x + 70y = 68x + 68y

63x - 68x = 68y - 70

-5x = -2y

5x = 2y

(x/y) = 2/5.

Possible values of x and y :

(i) (4,10)

(ii) (6,15)

(iii) (8,20).

(iv) (10,25)