part b: possibilities are: (1,1), (2,1) and (1,2) - 3 cases total. Of these, 1 is a double. So the conditional probability is 1/3.

part c: There are 6+6-1=11 cases where a 3 is rolled. So the probability is 11/36.

part d: Of the 30 cases where doubles aren't rolled, 10 have a 3 in them. So the conditional probability is 10/30.