This document discusses unions and intersections of sets and events. It defines a union as the set containing all elements that are in at least one of the sets being combined, while an intersection is the set of elements common to all sets being combined. Examples are given using Venn diagrams to illustrate unions and intersections of various sets. The objective is to illustrate and determine unions and intersections of events, and to appreciate their importance in real-life situations.

1. Objective:
a.Illustrate union and intersection of
events.
b. Determine the union and
intersection of two or more
events.
c. Appreciate the importance of the
lesson in the real life situations.
Unions and Intersections of Sets

2. What is a Union?
B
A

3. What is a Union?
B
A

4. Example
2 4
1 3
5 4 3
6 7
A B

5. Example
2 4
1 3
5 4 3
6 7

6. Union of
Events
The union of two or more sets refers
to the set with all the elements
belonging to each set. An element is
said to be in the union if it lies to at
least one of the sets. The symbol ∪ is
popularly used for union and its
association with the word “or”. This is
because A∪B is the set of all
elements in A or B or even both.

7. Example
2 4
1 3
5 4 3
6 7
Therefore: A∪B =
{1,2,3,4,5,6,7}

8. What is Intersection?
A B

9. Intersection of
Events
The intersection of two or more sets
refers to the set of elements universal to
each set. An element is in the
intersection if it occurs in all of the sets.
The symbol ∩ is used for intersection
and its association with the word “and”.
This is because A∩B is the set of
elements simultaneously pertaining to A
and B.

10. 1 3 5 7
2 4 6
1
A B
Therefore: A∩B =
{1}

11. 1 2 3 4
2 4 5 7
2 3 5 6
A B
C

13. VENN DIAGRAM
• A Venn diagram is a
diagram that shows all
possible logical relations
between a finite collection
of different sets. Venn
diagrams were conceived
around 1880 by John Venn.

14. Let’s Try