There is only one scoring method, because it is mixed doubles, so the referee can only be made by boys. Three boys draw different colors, and girls draw 1 red 1 green.
Boys draw first: 2x2x1xa (3,3) = 24 kinds.
Female students flinch: A (2,2) = 2 kinds.
Multiplication principle: 24x2=48 kinds.
The total drawing method is: a (5,5) =120 kinds.
The probability is 48/ 120=2/5.
The main idea is thinking, and the results are for reference only!