Why a fraction whose denominator 13 is in simplest form?

Answer 1

A fraction with a denominator of 13 could be in its simplest form because 13 is a Prime number and has only 1 and 13 as divisors.

However not every fraction with a denominator of 13 is in its simplest form. see below..

13/13 = 1/1 =1

39/13 = 3/1 =3

Answer 2

A fraction with a denominator of 13 is in simplest form when the numerator and denominator have no common factors other than 1. This is because if there were common factors, the fraction could be further reduced. For example, if the fraction were 26/52, it could be simplified to 1/2 because both 26 and 52 share a common factor of 2. Therefore, a fraction with a denominator of 13 is in simplest form when it cannot be reduced any further.