1. The problem asks to identify the independent variable given two variables: $c$ (number of costumes) and $d$ (number of dances). 2. By definition, the independent variable is the one that you control or choose values for, and the dependent variable depends on the independent variable. 3. The problem states two scenarios: - $c$ is independent and $d$ is dependent. - $d$ is independent and $c$ is dependent. 4. To determine which is the independent variable, consider the context: the number of dances $d$ likely depends on how many costumes $c$ are available, or vice versa. 5. Since the question asks "What letter is the independent var?" and the first statement says $c$ is independent and $d$ is dependent, the independent variable is $c$. 6. Therefore, the independent variable is $c$. Final answer: $c$ is the independent variable.