Final answer:
The type of variables that may be simple or multiple depending on the number of independent variables present are discussed in the context of Mathematics.
Step-by-step explanation:
The subject of this question is Mathematics. The question is asking about the type of variables that may be simple or multiple depending on the number of independent variables present. In statistics, when studying the relationship between variables, there are independent variables and dependent variables. The independent variable is the variable being controlled or manipulated in an experiment, while the dependent variable is the variable that is being observed or measured and depends on the independent variable.