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Bus trip - PS

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Bus trip - PS

by karthikpandian19 » Thu Dec 15, 2011 11:41 pm
A bus trip of 450 miles would have
taken 1 hour less if the average speed S
for the trip had been greater by 5 miles
per hour. What was the average speed S,
in miles per hour, for the trip?
(A) 10
(B) 40
(C) 45
(D) 50
(E) 55
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by ankush123251 » Thu Dec 15, 2011 11:49 pm
Many methods to solve this but the most algebraic one is:
D= S * t

Let s be average speed and t be the initial time without any increase in speed.
So,
450 = S * T

Then,from the given information,

450 = (S+5) * (T-1)
Solve for S from both equations we have S = 45.

Hope this helps....
You can see options and solve directly also by trying the options.For this always start with option E and backwards.
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by ankush123251 » Thu Dec 15, 2011 11:50 pm
Many methods to solve this but the most algebraic one is:
D= S * t

Let s be average speed and t be the initial time without any increase in speed.
So,
450 = S * T

Then,from the given information,

450 = (S+5) * (T-1)
Solve for S from both equations we have S = 45.

Hope this helps....
You can see options and solve directly also by trying the options.For this always start with option E and backwards.
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by karthikpandian19 » Fri Dec 16, 2011 12:07 am
Thanks,

Is there any other method other than Algebra?
ankush123251 wrote:Many methods to solve this but the most algebraic one is:
D= S * t

Let s be average speed and t be the initial time without any increase in speed.
So,
450 = S * T

Then,from the given information,

450 = (S+5) * (T-1)
Solve for S from both equations we have S = 45.

Hope this helps....
You can see options and solve directly also by trying the options.For this always start with option E and backwards.
Top
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Posts: 49
Joined: Thu Feb 17, 2011 1:36 am
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by ankush123251 » Fri Dec 16, 2011 12:36 am
As i said try out the options directly and if you are lucky you can get the answer in 20 seconds!!!
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by ankush123251 » Fri Dec 16, 2011 12:36 am
As i said try out the options directly and if you are lucky you can get the answer in 20 seconds!!!
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