The student's council is setting up a concession stand for a 24 hour relay. They plan on selling hot dogs and hamburgers. A maximum of 600 hamburgers and hot dogs are needed. From the previous year's relay the demand should be at least four times as many hot dogs as hamburgers. Define the variables.

The variables in a mathematical expression are the elements in the function in which essentially, varies. For example, one variable here is time. of course, the number of hotdogs and concessionaires sold depends on the time at which they are available to customers. Another variable the dependent one is the number of food items sold.