1) A box contains 5 red marbles, 10 white and 15 black.
If 3 marbles are drawn in succession and without replacement. What
is the probability that they are all different colors?
2) In three urns, red, white and blue colored
marbles are placed, distributed as follows. An urn is selected at
random and a marble is drawn at random. What is the probability
that the urn is III, given that the marble is red?
RED
WHITE
BLUE
URN
5
3
2
URN
1
8
1
URN
3
1
6