(2)(a) Perhaps it will help by drawing a tree diagram. This is an example of a conditional probability.
Let R be the event of the first cube drawn is red and Q the event of drawing at least 2 red cubes.
P(Q n R)=P(RRB)+P(RBR)+P(RRR)
P(Q|R)=P(R n Q)/P(R)
(b) You can do the same here but this time its drawing without replacement.