7. A police officer predicts that the average speed, s, in miles per hour on a certain section of road varies inversely as the number of cars, n, increases. a. If 20 cars on that section of road are moving at an average speed of 35 miles per hour, what is the inverse variation function that describes this relationship?

b. Using the function you found, for what number of cars, n, should the police officer expect the predicted average speed, s, to be greater than 70 mph? ​