Answer:
His average speed for the whole Journey is 60 km/h
Step-by-step explanation:
Mathematically;
Average speed is total distance/total time
taken
First part , 10 km in 40 minutes
40 minutes = 40/60 = 2/3 hours
Second part ; 8 km in 35 minutes
35 minutes = 35/60 = 7/12 hours
Total time = 2/3 + 7/12 = (8 + 7)/12 = 15/12 = 5/4 hours
Total distance = 10 + 8 = 18 km
Average speed = 18 km divided by 5/4 hours
5/4 hours = 1.25 hours
So average speed in km/h will be 75/1.25 = 60 km/h
