A={bb;bg;gb}
P(A)=P(bb)+P(bg)+P(gb)=62⋅51+62⋅51+61⋅52=302+302+302=306=51
B={bb;bg;br;gb;rb}
P(B)=P(bb)+P(bg)+P(br)+P(gb)+P(rb)=62⋅51+62⋅51+62⋅53+61⋅52+63⋅52=302+302+306+302+306=3018=53
C={rb;rr}
P(C)=P(bb)+P(rr)=62⋅51+63⋅52=302+306=308=154
D={bb;bg;gb}
P(D)=P(bb)+P(bg)+P(gb)=62⋅51+62⋅51+61⋅52=302+302+302=306=51