Bernard drove for 6 hours at an average speed of 116 km/h to reach town. For the first 262 km of the journey, he drove at 131 km/h. Find the average speed of the remaining of the journey. (Round off your answer to 1 decimal place)
okay,
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CPhill's answer is very good but I will try and break it down further.
First look at the whole trip.
6 hours at 116km/hr will take the car 6*116 = 696km
So the whole trip is 696km and will take 6 hours.
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Now I am going to look at the first part of the trip.
You travel 262km at a speed of 131km/hour
It will help if you understand that 131km/1hour is the same as 1hour/131km
That is if you go 131km in an hour then you must take 1 hour to travel 131km.
I want to know how long this part of the journey took.
1hour131km×262km1
the km cancel out and you are left with 262131hours=2hours
So for this first stretch you travel 262km in 2 hours
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Now you need to know the average speed for the second part of the trip.
speed = distance/time
So you need distance and time taken.
The whole trip took 6 hours. The first part took 2 hours. So the second part must have taketn 6-2=4 ours
I worked out that the whole distance was 696km. The first part was 262km. So the second part has to be 696-262=434km
Speed for the second part is 434km/4hours = 108.5Km/hour
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I hope that that helps.
If he drove 6 hrs. at 116km/hr., the total length of the trip was 6hrs * 116km = 696km
And he travels 262km in the first 2 hours. So the distance left to travel in the last four hours was :The total distance traveled (696) - the distance already traveled (262) = 434km
So, the final 4 hrs Bernard traveled 696 - 262 = 434km
And Distance/Time = Rate......... so
434km/4hrs = 108.5 km/hr
And that's the rate for the rest of the trip.
sorry CPhill i actully cant understand ur answer proplerly ! im getting a bit confused ?
okay,
Thank you for telling us that you didn't understand - We need your honest feed back. Just make sure you think really hard first. But if you still don't understand - Always say so.
-----------------------------------------------------------------------
CPhill's answer is very good but I will try and break it down further.
First look at the whole trip.
6 hours at 116km/hr will take the car 6*116 = 696km
So the whole trip is 696km and will take 6 hours.
--------------------------------------------------------------
Now I am going to look at the first part of the trip.
You travel 262km at a speed of 131km/hour
It will help if you understand that 131km/1hour is the same as 1hour/131km
That is if you go 131km in an hour then you must take 1 hour to travel 131km.
I want to know how long this part of the journey took.
1hour131km×262km1
the km cancel out and you are left with 262131hours=2hours
So for this first stretch you travel 262km in 2 hours
-------------------------------------------------------------------------
Now you need to know the average speed for the second part of the trip.
speed = distance/time
So you need distance and time taken.
The whole trip took 6 hours. The first part took 2 hours. So the second part must have taketn 6-2=4 ours
I worked out that the whole distance was 696km. The first part was 262km. So the second part has to be 696-262=434km
Speed for the second part is 434km/4hours = 108.5Km/hour
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I hope that that helps.