How is a mixed number defined?

A mixed number is defined as a combination of a whole number and a fraction. This means it consists of both an integer part, which represents the whole number, and a fractional part, which indicates the portion of a whole that is not yet completed. For example, in the mixed number 3 1/2, the '3' is the whole number, and '1/2' is the fraction. This format is useful for expressing quantities that involve both whole units and additional parts.

In terms of the context of other definitions, whole numbers alone do not capture the fractional component that makes a mixed number unique. A fraction greater than one whole can be a mixed number if it includes its whole part in the mixed format, but defining a mixed number merely as a fraction overlooks the essential combination aspect. Lastly, a fraction that cannot be simplified does not relate to the concept of mixed numbers, as it does not incorporate a whole number. Thus, option C accurately encapsulates the defining characteristics of a mixed number.