I am choosing to solve this way:
If there are 2 teams - both groups are divisible by 2. (8 b & 10 g). That works.
If there are 3 teams - you cannot divide 16 or 20 by 3 evenly.
If there are 4 teams - you can divide into 4 b and 5 g on each team. That works.
5 teams doesn't work because 16/5 would leave one boy left over.
6 teams, doesn't divide equal for boys or girls.
7-10 teams doesn't divide evenly.
2 teams is our greatest number of teams possible.
