Which number set does NOT represent common fractions?

A common fraction is defined as a way to express a part of a whole using two integers - a numerator and a denominator. Options A, B, and D all fit this definition, as they consist of integers in the form of a fraction where the numerator (the number on top) is divided by the denominator (the number on the bottom).

The number represented by option C is 3.0, which is a decimal representation of a whole number and does not fit the definition of a common fraction. While decimal numbers can represent values that relate to fractions (like 0.75 representing 3/4), they are not fractions in their own right. Therefore, in the context of common fractions, 3.0 is the only choice that does not represent a common fraction.