The right answer is 88 km/h
To answer this exercise, it is necessary to calculate the total travel time, and the total distance traveled, so we can calculate the average speed.
The total time travel = 0.4 hour + 0.6 hour = 1 hour.
The total distance traveled is: 35 + 53 = 88km.
Average speed = distance / time = 88/1 = 88 kilometers per hour.
