The Willis Tower is 1450 feet tall. Jeff
wanted to make a scale model for his
class project, but his mother's car can
hold only a 36 in. tall model. What scale
factor should Jeff use to create his
model?

  something smaller than 1/483.33, possibly 1/500

Step-by-step explanation:

For the model to fit into the car, the scale must be less than ...

  (3 ft)/(1450 ft) = 1/483.33

It might be convenient for Jeff to use a scale factor of 1 : 500. This would result in a model ...

  (1450 ft)/500 · (12 in/ft) = 34.8 in

leaving about 1.2 inches of clearance in his mother's car.