1. The problem statement, all variables and given/known data A bag has a total of 12 balls, 3 of which are black. If you select 6 balls from the bag. a) How many sets of 6 can be made? b) How many of the sets of 6 contain 3 black balls? c) What is the probability of selecting a set of 6 that contains 3 black balls? 2. Relevant equations NPR NCR 3. The attempt at a solution Part a) I believe 12C6 gives the total of sets of 6 = 924 Part b) I believe 9C6 gives the total of sets of 6 of white balls only so (12C6) - (9C6) = sets that have 3 black? Part c) [ 12C6 - 9C6 ] / 12C6 ?