speed = distance/time
What was the runner doing from point B to point C?
What is stopped?
How far did the runner travel from point C to point D?
What is 9 km?
What is the displacement of the runner for this journey?
What is 0 meters?
What was the total distance traveled by the runner?
What is 24 kilometers?
What is the importance of a distance/time graph?
A distance-time graph shows how far an object has travelled in a given time.