Answer:
a) Turned around and went back to their starting point
b) 8km/h
Explanation:
a) the numbers on the left running vertically show the distance covered. When the line goes down again, it shows that Jo was taking away from the distance covered. After 10 minutes, Jo turned and went back to their starting point.
b) from 30 mins to 60 mins is half an hour. In that time, Jo covered 4km and therefore, if they continued at the same speed, in 1 hour (30 mins x 2), Jo would have covered 8km (4km x 2).
∴ Jo is travelling at 8km/h for the last half hour.
I hope this was helpful :-)