## 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 … Read more3.2b Universal Sets

## 3.2a Subsets

3.2a Subsets 1. If every element of a set A is also an element of a set B, then set A is called subset of set B. 2. The symbol ⊂ is used to denote ‘is a subset of’. Therefore, set A is a subset of set B. In set notation, it is written as A⊂B. Example: A = {11, 12, … Read more3.2a Subsets