Loading...
Experiments, Sample Spaces, and Events
A
B
C
D
. . . .

Operations on Events

Definition
Consider two events A and B. The union of events A and B is the set containing all the elements that are in A, in B, or in both A and B. The union of A and B is denoted by A∪B.

Example 1

Consider the experiment of tossing a die. Let A be the event of obtaining a number less than 4. Let B be the event of obtaining an odd number. Determine A∪B.


Solution

Based on the given information, A={1,2,3} and B={1,3,5}. Thus, A∪B={1,2,3,5}.

In getting the union of two events, the elements common to both events are not repeated. In the example above, the elements 1 and 3 are both in events A and B but are written only once in A∪B.