The number 23 belongs to the following sets:
- Rational Numbers - because it can be expressed as a fraction (23/1).
- Integers - because it is a whole number.
- Whole Numbers - because it is a non-negative integer.
- Natural Numbers - because it is a positive integer.
Since 23 does not belong to the set of Irrational Numbers, the correct answer that includes all relevant sets is:
Enter Number 1: Rational Numbers, Integers, Whole Numbers, Natural Numbers
So, the corresponding answer is 1.