The sum of the three can be rational or irrational.
No. In fact the sum of a rational and an irrational MUST be irrational.
It is always irrational.
Such a sum is always irrational.
The sum is irrational.
The value of the sum depends on the values of the rational number and the irrational number.
An irrational number.
It is an irrational number.
Any, and every, irrational number will do.
The sum of two irrational numbers may be rational, or irrational.