Formula Review

Subsets

The number of subsets of a finite set AA is equal to 2 raised to the power of n(A)n(A), where n(A)n(A) is the number of elements in set AA: Number of Subsets of Set A=2n(A)A=2n(A).

Set Operations with Two Sets

The cardinality of AA union B:n(A∪B)=n(A)+n(B)−n(A∩B)