Answer: 3 inches per foot.
Explanation:
Given: A ramp with a constant incline is made to connect a driveway to a front door.
At a point 4 feet from the driveway
, the height
of the ramp is 12 inches.
At a point 6 feet from the driveway
, the height
of the ramp is 18 inches.
The rate of change of the ramp’s incline is given by :-

Hence, the rate of change of the ramp’s incline is 3 inches per foot.