[填空题]
A bag contains 8 blue marbk()aqfhpm1x .* aus6tles and 4 red mare8 fi d,n ng9f5s2kx0ybles.
Ray selects two marbles from the bag in succession, without replacement.
1.Complete the missing probabilities on the tree diagram below.
2. Determine the probability of:
(1) Ray selecting two red marbles.≈
(2) Ray selecting two marbles of different colour.≈