By definition, a rational number is a number q that can be written as a fraction in the form q=a/b where a and b are integers and b≠0. so, 1/3 is rational because it is exactly what you get when you divide one integer by another. sep 22, 2015

Numbers are classified in many ways. One of which is that some are classified as rational. These numbers are those whose values can be expressed in terms of the ratio of two numbers. These may be those repeating and non-repeating. There are also irrational numbers which are non-repeating and cannot be expressed as the ratio of two numbers. 

Okay i will add you