Stage 32 · Counting, Permutations, Combinations & the Binomial Theorem
32.3.3 Two Properties of Combinations
32.3 Combinations: Only Who Was Chosen, Not the Order
Point 3 of 6
32.3.3 Two Properties of Combinations
Core ideaChoosing m is the same as 'rejecting the other n-m', so C(n,m) = C(n,n-m); add to that C(n+1,m) = C(n,m) + C(n,m-1)
Module goal. Tell combinations apart from permutations, master the combination formula and its two key properties, and solve combinations with restrictions plus simple distribution problems