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?

Answer 1

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

g = 42-b, so

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