Which of the following describes the function shown in the table below?

x
y
-4
16
-1
2
2
0.25
4
0.0625
5
0.03125
exponential, there is a constant rate of growth
exponential, there is a constant rate of decay or decrease
quadratic, there is a second degree change in the y-values
quadratic, there is a constant difference between consecutive y-values

B: exponential, there is a constant rate of decay or decrease

Step-by-step explanation:

Because there is a constant decay rate of  

f(x)=0.5^x

- "runner b is moving at a slower rate."

- "the graphs shown are graphs of distance(km) against time(min).

the slopes of this graphs are are given by:

slope = (change in y)/(change in x)

= (change in distance)/(change in time)

this is the formula for finding the speed. so, the slope of these graphs represent the speed of the runner.

taking each division in the graph to represent 1 on both axis:

runner a ⇒ speed = (2-0)/(1-0)

= 2/1

= 2 km/min

runner b ⇒ speed = (3-0)/(3-0)

= 3/3

= 1 km/min

this shows that   runner b is moving at a slower rate."