A car travelled from Agra to Jaipur at an average speed of 30 km/hr . On his return journey, his average speed was 45 km/hr . If total time taken is 8.5 hours, find the distance between Agra and Jaipur.
Answers
Answer:
As soon as you read the word average, it becomes tempting to simply add up the speeds and halve them to get the answer. But this logic is flawed.
Let’s get back to the definition of average speed.
Average speed is the total distance travelled by an object divided by the total time taken to cover that distance.
Let us say the distance between delhi and agra is ‘d’ kms. So for a return trip, our guy covers a total distance of ‘2d’ kms.
From Delhi to Agra:
Speed = 30km/h
Time = d/30 hrs (because time = distance/speed)
From Agra to Delhi:
Speed = 60km/h
Time = d/60 hrs
To sum up:
Total distance travelled = 2d kms
Total time taken = d/30 + d/60 hrs
Avg speed = Total distance / Total time
On calculation,
Avg speed = 40 km/h
Step-by-step explanation:
hope this helps please mark me brainlist I