A car travels a certain journey at 40 km/h and an equal distance more at 60 km/h. The average speed for the whole journey is:
48 km/h
The correct answer is 48 km/h.
Because more time is spent traveling at the slower speed (40 km/h), the average speed will be weighted more towards 40 km/h than 60 km/h. Therefore, the average speed must be less than the arithmetic mean (50 km/h) and closer to 40 km/h. Our calculated average speed of 48 km/h is indeed less than 50 km/h, which makes sense intuitively because more time was spent at the slower speed of 40 km/h than at the faster speed of 60 km/h (for equal distances).
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Important Questions from Average Speed
A person covers a certain distance at the speed of 60 kmph and returns to the starting point at a speed of 40 kmph . Find the average speed (in km/hour) of the person for the whole journey.
Kapil travels for 4.5 hours at a speed of 50 km / h and 7.5 hours at a speed of 70 km / h. At the end of it, he finds that he covered only 6/7 of the total distance. At what average speed should he travel so that the remaining distance traveled in 5 hours?
A car has to cover 125 kms in 5 hours. What will be the average speed of the car if it has covered 90 kms in the first 3 hours?
A scooter from P to Q travels at 40 km/h and from Q to P at 30 km/h. What is the average speed of the scooter?
To cover a distance of 144 km in 3.2 hours what should be the average speed of the car in meters/second?
