Answer:
90km/h
Step-by-step explanation:
The average speed is the total distance travelled/the time taken to do so. Being a distance-time graph, it shows that the car travelled 60km away from the starting point, stayed for a bit and then drove back. This gives a total distance of 120km. It also says that they started at 7:00am and finished at 8:20am which is 1 and 1/3 hours or 1.33 hours (1 hour 20minutes).
120/1.333...=90
Their average speed for the entire journey was 90km/h.
Hope this helped!
