Ali is walking. the number of calories he has burned varies directly with the number of minutes he has walked. see the graph below.

step-by-step explanation:

you can see from the graph that, for example, ali burned 50 calories in 10 minutes. therefore he walkes 10/50=0.2 minutes per calorie burned.

the slope is the calories burned per minute, or 50/10=5.

answer: a.

step-by-step explanation: the answer is a. because, you need to converge the fractions to find a solution.

- "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."