Henry has $21.50 to ride the trolley around San Francisco this week. It will cost him $0.50 every time he rides. Identify the dependent variable and independent variable in this scenario. The number of rides and the total cost are both independent variables. The number of rides and the total cost are both dependent variables. The total cost is the independent variable, and the number of rides is the dependent variable. The number of rides is the independent variable, and the total cost is the dependent variable.