Understanding Cardinality in Set Theory

This video tutorial explains how to find the cardinality of the union and intersection of two sets. It introduces the concept of cardinality, the universal set, and the use of Venn diagrams to visualize and solve set problems. The tutorial provides step-by-step guidance on identifying elements in the union and intersection of sets A and B, and how to complete a Venn diagram with elements from the universal set. Finally, it demonstrates solving set problems by calculating the number of elements in the union and intersection of sets.

What is the cardinality of a set?

• The number of subsets in a set

• The number of elements in a set

• The number of intersections in a set

• The number of unions in a set

What does the symbol for union represent?

• Not

• Or

• And

• If

Which elements are in both sets A and B?

• 2, 4, 6, 8, 10

• 12, 14, 16, 18, 20

• 1, 6, 8, 14, 16

• 3, 5, 7, 9, 11

Which elements are only in set A?

• 4, 11, 15, 17, 18, 19, 20

• 3, 5, 9, 13

• 1, 6, 8, 14, 16

• 2, 7, 10, 12

Which elements are only in set B?

• 3, 5, 9, 13

• 4, 11, 15, 17, 18, 19, 20

• 2, 7, 10, 12

• 1, 6, 8, 14, 16

Which elements are in the universal set but not in A or B?

• 4, 11, 15, 17, 18, 19, 20

• 3, 5, 9, 13

• 1, 6, 8, 14, 16

• 2, 7, 10, 12

How many elements are in the universal set?

• 25

• 20

• 15

• 10

What is the cardinality of A union B?

• 10

• 16

• 12

• 20

What is the cardinality of A intersect B?

• 5

• 6

• 4

• 3

How can we verify the cardinality of A union B?

• By adding elements in A and B

• By subtracting elements not in A or B from the universal set

• By counting elements in the universal set

• By listing all elements