The ratio of boys and girls in a class is 5:3 if 20 % of the boys and 60 % of girls have passed in first class what percentage of the class is in first class?

let the number of boys be 5x and the number of girls be 3x

total students = 8x

students in 1st class = .2(5x) + .6(3)
= 2.8x

percentage in 1st class
= 2.8x/(8x)
= 28/80
= .35 or 35%