There are 42 student in a class 3/4 of the boys and 2/3 of the girls travel to school by bus. The total number of boys and girls who come to school by bus is 30. How many boys are there in the class?

1 answer

b+g=42
3/4 b + 2/3 g = 30

g = 42-b, so

3/4 b + 2/3 (42-b) = 30
b = 24