PROBABILITY

10 random Cars

6 Red 12 Silver 5 Black

WHAT ARE THE PROBABILITY OF:

a. 4 cars are red the rest silver

b. 5 cars are red 5 are black

c. Exactly 6 cars are red

What I have worked on:

23c10=1144066

a. 6c4*12c6 / 1144066

b. 6c5*5c5

c. 6c10

How do I set this up?

thank you in advance