Question

Identify the finite and infinite sets and find the cardinal numbers of the finite sets$.$

$B=\{x:x<5$and $x\in W\}$

Answer 1

The set$-$builder form of a set is $B=\{x:x<5$and $x\in W\}$

In the given set there are whole number less than $5$

$B=\{0,1,2,3,4\}$

In this set there are finite number of elements

The number of elements in the given set $B$ is $5$

$n\left(B\right)=5$

Hence$,$ the given set is a finite set and its cardinal number is $5$.