Combinatorics lock puzzle
15349
Combinatorics riddle: keys and a safe
68882
Path to Combinatorics Problem [$1.11$]
152333
A problem based on pigeonhole
13860
IMO/1981 - Combinatorics
38037
A problem with my reasoning in a problem about combinations
48914
Monty Hall Three-Door Puzzle
5801
Combinatorial proof help
101642
Counting in a rectangular grid with obstacles
39724
Combinatorial Identities
144025
Number of Solutions in this Number Puzzle
143573
Problem (1.8) A Path to Combinatorics Solution Verification.
93459
Number of permutations of unspecified length
134440
An unexpected application of non-trivial combinatorics
17580
Combinatorics That Looks Similar to Vandermonde's Identity
35648
How many permutations of the set n={1,2,3,3,3,4,4,5} are possible without any consecutive identical elements?
108941
Combinatorics Question Asking How Many Integer Solutions Given Different Restrictions
45074
Combinatorics: Selecting objects arranged in a circle