A car covers the first 120 km at 40 km/hr, the next 180 km at 60 km/hr, and the last 100 km at 50 km/hr. Find the average speed of the car for the entire journey.
50 km/hr
Total distance \(= 120 + 180 + 100 = 400\) km.
Time for each leg: \(\dfrac{120}{40} = 3\) hr, \(\dfrac{180}{60} = 3\) hr, \(\dfrac{100}{50} = 2\) hr.
Total time \(= 3 + 3 + 2 = 8\) hr.
Average speed \(= \dfrac{\text{total distance}}{\text{total time}} = \dfrac{400}{8} = 50\) km/hr.
Hence, the average speed for the entire journey is 50 km/hr.
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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.
A train runs at a speed of 28 kmph for 4 hours and 30 kmph for 5 hours and the remaining 40 kms in one hour. What is the average speed per hour?
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?
