Distance / time is simply called "speed". When the direction is relevant, you would talk about "velocity". I am not aware of different "types of speed".
The average speed
A straight line on a distance/time graph means that the speed is constant. In every unit of time the distance increases by the same amount.
Speed-Versus-Time, Distance-Versus-Time.
That will give you the average speed during that particular period of time.
The basic formula for this type of speed problems is: distance = speed x time. Solving for time: time = distance / speed. In this case, the answer will be in hours.
Distance traveled and time taken to travel that distance.
Distance*speed divided by time
Any type of measurement is a unit rate. The speed limit is a measurement of time and distance.
For this type of speed problems, please use the basic speed equation for speed: distance = speed x time In this particular case, you simply need to divide the distance by the speed.
Speed is the magnitude of velocity, or the rate of change of distance.
I assume you mean "40 miles per hour". For this type of problems, you use the formula:distance = speed x time In this case, you solve for time, i.e., you divide the distance by the speed.
Speed, reaction time, car's mass, tires, mechanical condition & type of brakes.