Of 91 cars making up a freight train, 57 are boxcars. What fraction of the cars are not boxcars?
The fraction of cars that are not boxcars can be calculated by subtracting the number of boxcars from the total number of cars and then dividing by the total number of cars.
Total number of cars = 91
Number of boxcars = 57
Number of non-boxcars = 91 - 57 = 34
Fraction of cars that are not boxcars = 34/91
Therefore, 34/91 of the cars are not boxcars.