Answer
between 9.5 and 42.3
Work Step by Step
1. We graph the function as shown in the figure.
2. Draw a horizontal line $y=40$ and we can find two intersection points as
$(9.5,40)$ and $(42.3,40)$ as shown in the figure.
3. For the number of cars that pass by the given point to be greater than 40,
the corresponding region of x can be find as from 9.5 to 42.3
