Problema Solution
the number of girls varied inversely as the number of boys and directly as the number of teachers. when there were 50 girls, there were 20 teachers and 10 boys. how many boys were there when there were 10 girls and 100 teachers.
Answer provided by our tutors
let
b = the number of boys
g = the number of girls
t = the number of teachers
g = k*t/b, where k is a constant
when there were 50 girls, there were 20 teachers and 10 boys that is
g = 50 girls, t = 20 teachers, b = 10 boys
50 = k*20/10
2k = 50
k = 25
thus the formula for the number of girls is
g = 25t/b
when g = 10 girls and t = 100 teacher we have
10 = 25*100/b
b = 25*100/10
b = 250 boys
there are 250 boys.