Inverse Property of rational number states that the multiplication of rational number with its inverse is unity that is 1. Inverse of rational number is simply inverting the rational number that is the numerator of the parent number become the denominator of the inverse number and the denominator of the inverse number becomes the numerator of the inverse number. Thus, if we multiply the original rational number with its inverse rational number that the result is always 1 .
For example let's take an example of rational number say 21/17,
Now its inverse is 17/21
Now, (21/17) * (17/21) = 1 ( Inverse property proved)
Let us take another example say 111/19
Inverse = 19/111,
Product = (111/19)*(19/111) = 1.