Counting Disjoint Pairs

★ 5/10combinatoricsCountingSet Theory

Problem

Let MM be a set with 66 elements, and define

T={(A,B)∣A,B⊆M, A≠∅, B≠∅, A∩B=∅}.T = \left\{(A, B) \mid A, B \subseteq M,\ A \neq \varnothing,\ B \neq \varnothing,\ A \cap B = \varnothing\right\}.

Find the number of elements of TT.

Answer

Solution

Difficulty5/10
Topicscombinatorics, Counting, Set Theory

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