A set of natural numbers is finite or not.
It is not a finite set. Because there are infinite numbers.
A set of natural numbers multiples of 7 less than 100 is finite or not.
A set {10,20,30,40,50} is finite or not.
A set of multiples of 5 is finite or not.
A set of schools in India is finite or not.
A set of natural numbers satisfying the equation2x=1is empty or not.