Question 1119229
Red2 Black 1 White 1
R-R probability is 1/2*1/3=1/6
R-B probability is 1/2*1/3=1/6
R-W probability is also 1/6
B-R probability is 1/4*2/3=1/6
B-W probability is 1/4*1/3=1/12
W-R probability is 1/6
W-B probability is 1/12

b. Both are red has probability 1/3
At least one is red has probability is 5/6
c.  If one ball is red (probability 1/2), both are red has probability 1/3, since if 1 is red, there are three other balls with three different colors, one of which is red, and that probability is 1/3