Explanation:
I think we are talking about boys and girls in the art club.
B = number of boys
G = number of girls
a ratio of 1:3 between B and G means that for every boy there are 3 girls in the art club.
that means
G = 3 × B = 3×8 = 24
so, in total there are
8 + 24 = 32
children in the art club.