How many 6-digit combinations AND permutations can be formed from the following set: {1, 1, 2, 2, 3, 3, 4, 4, 5, 5, 6, 6, 7,7, 8, 8, 9, 9}? Thank you.
My computer says there are:
1,554 combinations, and:
430,920 permutations.
Melody: Can you please see if you can replicate these numbers using combinatorics? Thanks.
