Question

What is the cardinal number of the following sets?

The set of inventions: telephone, pendulum, wheel and computer.

Answer 1

The number of distinct elements in a finite set is called the cardinal number of the set. It is denoted by $n\left(A\right)$

Given set:

The set of inventions: telephone, pendulum, wheel and computer.

The number of elements in the given set is $4$

Therefore, the Cardinal number of the set of inventions of telephone, pendulum, wheel and computer is $n\left(A\right)=4$

Hence, the cardinal number of the set of inventions: telephone, pendulum, wheel and computer is $4$.