3.2b Universal Sets

3.2b Universal Set
1. Universal set is a set that contains all the elements under consideration.
2. In set notation, the symbol ξ denotes a universal set.

Example:
Given that the universal set, ξ = {whole numbers less than 9}, A = {prime number} and B = {multiple of 4}.
(a) List all the elements of set A and set B.
(b) Illustrate the relationships between the following sets using Venn diagrams.
     (i) ξ and A
     (ii) ξ, A and B

Solution:
(a) ξ = {0, 1, 2, 3, 4, 5, 6, 7, 8}
     A = {2, 3, 5, 7}
     B = {4, 8}

(b)(i) 







(b)(ii)