Problema Solution
In a class, there are four more boys than girls. 1/3 of the girls and 7/11 of the boys take the train to school. If half of the class takes the train, how many boys and girls are there in the class?
Answer provided by our tutors
let
x = the total number of girls in the class
y = the total number of boys in the class
there are four more boys than girls
y = x + 4
1/3 of the girls and 7/11 of the boys take the train to school = half of the class takes the train
x/3 + 7y/11 = (x + y)/2
by solving the system of equations
y = x + 4
x/3 + 7y/11 = (x + y)/2
we find
x = 18 girls
y = 22 boys
there are 18 girls and 22 boys in the class.