Union (U); the union of any two or more sets is the lists of all elements in the set. Example:

Given that A= (1, 2, 3, 4, 5) and B= (2, 3, 5, 7) list AUB

AUB= (1, 2, 3, 4, 5, 7)

Intersection (n); the intersection of any two or more sets is the list of elements found in both sets. It is represented by “n”. Example:

 Given that A= (a, b, c, d) and B= (b, c, d, e, f), find (a) AnB (b) AUB (c) n(AUB)

Solution:

1. AnB= (b, c, d)    b) AUB= (a, b, c, d, e, f) c) n(AUB)= 6

Venn diagram

A venn diagram is a rectangular box used to represent the universal set and other sets as shown below;

N.B. the set A and B above are subset of Є and are inside the rectangle.

Intersection set:

Given two sets A and B, their intersection can be represented on a venn diagram by the shaded region below;

If the sets have no intersection, the venn diagram will look like;