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.
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