### CARDINAL NUMBER OF SETS

Some important results derived from Venn diagrams are as follows: A, B and C are three sets. \(\displaystyle n\left( \text{A}\cup \text{B} \right)=n\left( \text{A} \right)+n\left( \text{B} \right)-n\left( \text{A}\cap \text{B} \right)\) \(\displaystyle n\left( \text{A}\cup \text{B} \right)=n\left( \text{A} \right)+n\left( \text{B} \right)\Leftrightarrow \,\) A and B are disjoint sets. \(n\left( \text{A}-\text{B} \right)=n\left( \text{A} \right)-n\left( \text{A}\cap \text{B} \right)\) \(\displaystyle n\left( […]

### FINITE AND INFINITE SETS

A set having definite number of elements is called finite set. In other words, we can say that the number of elements of a set is defined called finite set. A set which is not having definite number of elements is called infinite set. Example: A = {1, 2, 3, 4, 5, ……………., 100} B […]