The sum of the three can be rational or irrational.
The square root of nine is three, and that is not an irrational number.
No, it is rational.
Because 3 is a prime number and as such its square root is irrational
Integers are rational. In the set of real numbers, every number is either rational or irrational; a number can't be both or neither.
Negative three is a rational number.
No, it is an irrational number.
No. The sum of an irrational number and any other [real] number is irrational.