Are all numbers rational

Answer 1

Yes. Any number that is not rational would not be called 'rational', and so

it would not be included in the bag of 'rational numbers'. So all the numbers

that are in there must be rational ones.

Answer 2

no

if yes, then why is there a term 'Irrational Numbers'?

examples of irrational numbers include:

sqrt(2), sqrt(3), sqrt (5), pi, e, 0.10100100010000010000001... etc.