You are a nascar fan that collects cars that are 1: 64 scale to the original car. if your collection has cars that ar 3 inches in lenth, theen what is the true length of a real nascar vehicle

The scale is 1:64.

Therefore if the length of the model is 3 inches, the true length of the vehicle is
3 * 64 = 192 inches  = 192/12 ft = 16 ft

16 feet 

If a scale is 1 : 64, it means that the original car is 64 times larger than a model.
Length = 3 in * 64 = 192 in
And since: 1 foot = 12 inches;
192 : 12 = 16 ft

The true length of a vehicle is 16 ft.

Were is the problem