At first, we should know that :
An Irrational Numbers : is a real number that cannot be written as a simple fraction.
A rational number : is a real number that can be written as a simple fraction.
So, for the option A.
![\sqrt[]{81}=9](https://img.qammunity.org/2023/formulas/mathematics/college/hrgr76taiv5j1qtpaini7j6mfty2s9db8b.png)
The number 9 is a rational number
So, the statement a is alse
For option B.

This number is the sum of :

So, the result will a rational number
so, the statement b is True