Final answer:
This question discusses set theory and cardinality in mathematics. It explains the union and intersection of sets A and B, along with the concept of set complements and the relationship between the probabilities of an event and its complement.
Step-by-step explanation:
The concept being discussed is related to set theory, which falls under mathematics. When we talk about the union of two sets, denoted as A ∪ B, we are referring to a set that contains all elements that are either in set A, set B, or in both. The provided information tells us that A AND B contains the elements {14,16,18}, which are common to both sets, and A OR B contains the elements {2, 4, 6, 8, 10, 12, 14, 15, 16, 17, 18, 19}, which lists all the individual elements from A and B combined, without repetition.
Regarding the concept of cardinality, it is the count of distinct elements in a set. The cardinality of A or B can be found by counting the number of elements in each respective set. Since the sets A OR B and A AND B are already defined, we can determine their cardinalities simply by counting their elements. Set A OR B, which is the union of A and B, has a cardinality of 12, since there are 12 distinct elements listed. Set A AND B, the intersection, has a cardinality of 3, reflecting the three common elements. Remember, for any set X, the complement of event X, denoted X', is the set of all outcomes not in X. For probabilities, P(X) plus P(X') is always equal to 1.