Question

Let S be the universal set, wiere:

S= {1, 2, 3, ..., 18, 19, 20}
Let sets A and B be subsets of S, where:
Set A=
= {1, 2, 3, 5, 7, 10, 11, 13, 18, 20}
Set B = {2, 4, 5, 6, 8, 11, 14, 15, 16, 17, 18, 19, 20}
Find the following:
LIST the elements in the set (A U B):
(AU B) = {
Enter the elements as a list, separated by commas. If the result is the empty set, enter DNE
LIST the elements in the set (AN B):
(AN B) = {
Enter the elements as a list, separated by commas. If the result is the empty set, enter DNE
You may want to draw a Venn Diagram to help answer this question.

Answer 1

A U B is the set containing all elements from both A and B:

A U B = {1, 2, 3, 4, 5, 6, 7, 8, 10, 11, 13, 14, 15, 16, 17, 18, 19, 20}

A ∩ B is the set containing all elements that are common to both A and B:

A ∩ B = {2, 5, 11, 18, 20}