for part a, could you just say that there are 11 possible outcomes (2,3,4,5,6,7,8,9,10,11,12) and that 4 of the outcomes are 9 and above, therefore 4/11 is the probability or .3636?
This wouldn’t be a good estimation, because getting a 12 has a much different probability than getting a 7 for example.
NO. Because each probability is not equal. There is only 1 way to get a sum of 5 but lots of ways to get a sum of 9. You cannot treat them equally!!!