Question

Classify the following as finite, infinite, singleton, or null sets. Also give the cardinal number of each set.

$\mathrm{B}=\{23,25,27,........55\}$

Answer 1

$B$ is a $\mathrm{finite}\mathrm{set}$, since it has countable elements present.

$B$ is a set of all odd numbers from $23\mathrm{to}55$

$\mathrm{B}=\{23,25,27,29,31,33,35,37,39,41,43,45,47,49,51,53,55\}$

Hence $n\left(B\right)=$ $17$