What is the definition of rational numbers?

Question

I am studying for EOC and forgot what the definition was and left my book at home.

Answer 1

a rational number is any number that can be put in the form a/b where a and b are integers and b≠0

any terminating decimal is a rational number and any repeating decimal is a rational number

a non-ending, non-repeating decimal is an irrational number

examples are pi (3.14159...) and the number e (2.71828183...-Euler's number) as well as √2, √3, √5, and infinitely other numbers