The common factor of the numerator and denominator of a rational number in its standard form is always ___.

A rational number can be expressed as the ratio of two integers, such as a/b where a and b are integers and b is not equal to zero.

A rational number is reduced to its standard form by dividing its numerator and denominator by their respective HCFs (Highest Common Factor). In the standard form of a rational number, the common factor of its numerator and denominator is always 1.