The distance between two cities is 220 km. A car covers 140km of the distance at 70 km/hr and the remaining distance at 50 km/hr taking a break of 1 hour in between. Find the average speed of the car for the whole journey.
Answers
Answer:-
Given:-
Distance between two cities = 220 km
Distance covered with the speed of 70 km/hr = 140 km
We know that,
Time = Distance/Speed
So,
⟹ Time taken to cover first 140 km = 140/70 = 2 hrs.
Now,
Remaining Distance = (220 - 140) km = 80 km
Speed of the car = 50 km/hr
⟹ Time taken to cover 80 km = 80/50 = 1.6 hrs.
It is also given that, it takes a break of 1 hr in between.
Therefore,
- Total time taken to cover 220 km = (2 hrs + 1.6 hrs) + 1 hr = 4.6 hrs.
Now,
We know that,
Average speed = Total distance covered/total time taken
- Total distance covered = 220 km
- Total time taken = 4.6 hrs
⟹ Average speed of the car = 220/4.6
∴ Average speed of the car = 47.8 km/hr
Given :-
The distance between two cities is 220 km. A car covers 140km of the distance at 70 km/hr and the remaining distance at 50 km/hr taking a break of 1 hour in between
To Find :-
Find the average speed of the car for the whole journey.
Solution :-
We know that
Time = Distance/Speed
In Case 1
Distance = 140 km
Speed = 70 km/h
Time = 140/70
Time = 2 hr
Now
Since, he takes a break of 1 hour.
So, Time taken before covering the remaining distance = 2 + 1 = 3 hr
Now
In Case 2
Distance = 220 - 140 = 80 km
Speed = 50 km/h
Time = 80/50
Time = 8/5 hr
Time = 1.6 hr
Total time = 3 + 1.6 = 4.6 hours
Total distance = 220 km
Avg. Speed = Total distance/Total time
Avg. Speed = 220/4.6
Avg. Speed = 2200/46
Avg. Speed = 47.82 km/h
Therefore, Average speed of journey is 47.82 km/h
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