Question 972075
There are 20 marbles
Prob of blue is (12/20) and green is (2/20).  There is no joint probability, so the answer is 0.7
For a blue and a red, the numerators are 12 and 6, so the probability is 0.9

There are 36 outcomes, and they form a pyramid with
roll 2=1
3=2
4=3
5=4
6=5
7=6
8=5
9=4
10=3
11=2
12=1

The probability of rolling a 7 is (1/6)
The probability of a 5 or a 11 is also (1/6) from the above.