A real number is rational iff its decimal representation is either terminating or re occuring. While a real number is called irrational if it is not a rational or its decimal representation is neither terminating non recurring.

Mathematically, a real number x s.t. x=p/q (q is non zero and gcd(p,q)=1), and p,q both are integers,is called rational number.

Interview questions:

Pi is rational or irrational number? And what you say about 22/7 whether it is rational or irrational?

Generally students get confused as they think pi and 22/7 both are same. but remember pi is approximately equal to 22/7 not exactly.

So clearly 22/7 is rational and pi is irrational number. For more details please refer below

Order Axioms are given ( refer the above notes) with the help, you can answer a lot of questions in higher education interviews.