In a math exam, the average score of a class is 83, of which the average score of girls is 85, and the number of girls is boys.
Grade six students scored an average of 85 points in the mid-term exam, including 88 points for boys and 83 points for girls. The ratio of boys to girls in this class is (2:3).
There are X boys. Girls and people.
88x+83y is the total score of the class.
85(x+y) is also the total score.
So 88x+83y=85(x+y),
88x+83y=85x+85y,
3x=2y,
x/y=2:3