Six 6-sided dice are rolled. What is the probability that exactly two of the dice show a 1 and exactly three of the dice show a 2? Express your answer as a common fraction.
You can also verify it this way:
1 - Calculate ALL the "combinations" first, then convert the "combinations" into "permutations":
The combinations are: 112223, 112224, 112225, 112226.
Each combination has this many permutations: 6! / [2!.3!] =720 / 12 =60 permutations each.
60 x 4 = 240 / 6^6 = 5 /972
