The total distance of a journey is 120 km. If one goes by 60 km/h and comes back at 40 km/h. What is the average speed during the journey?
The total distance of a journey is 120 km. If one goes by 60 km/h and comes back at 40 km/h. What is the average speed during the journey?
Explanation
To find the average speed:
Total distance = 120 km * 2 (to and fro) = 240 km
Time taken to go = 120 km / 60 km/h = 2 hours
Time taken to return = 120 km / 40 km/h = 3 hours
Total time = 2 + 3 = 5 hours
Average speed = Total distance / Total time
= 240 km / 5 hours
= 48 km/h