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If the speed of X meters per second is equivalent to the spe [#permalink]
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04 Jun 2009, 21:39
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If the speed of X meters per second is equivalent to the speed of Y kilometers per hour, what is Y in terms of X? (1 kilometer=1000 meters) A. 15x/18 B. 6x/5 C. 18x/5 D. 60x E. 3600000x
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Re: speed/conversion problem [#permalink]
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05 Jun 2009, 02:47
To convert Y Km/Hr to Metre/second just multiply it by 1000/(60*60)
1000Y/3600 and this is equal to X
Hence 1000Y/3600 = X => Y = 18X/5



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Re: help solving problem [#permalink]
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09 May 2010, 22:40
y=18/5x
meters>km is a factor of 1000
seconds > hrs is a factor of 3600 (or 60sec/min times 60min/hr)
3600/1000 = 18/5. Did I do this right?
Let me try slower:
Meters/sec times 1KM/1000meter =KM/sec; Km/sec times 60 sec/min times 60 min/hr =km/hr. so we divide by 1000 and multiply by 3600. Yep I think I got it.



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Re: help solving problem [#permalink]
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10 May 2010, 02:25
Is it not 5/18 and not 18/5 ?
km/hr is Y m/s is X
what is Y in terms of X implies express Y in X which is
1000/3600X = 10/36X
Y=5/18X.
Please correct.



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Re: speed/conversion problem [#permalink]
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14 Dec 2010, 00:48
For conversions try to understand the basic fundamental through the below explanation;
Example #1)
1 mile= 1.61km
so 15.7 miles =? km
Soln: PRINCIPLE/METHODOLOGY:
Convert the eqn to a fraction with the desired units on top and the given units on the bottom i.e. to convert from miles to kilometers you need a fraction with the desired units (KM in our case) on THE TOP and the given units (Miles) on THE BOTTOM.
= 1.61km/1mile
Now the solution becomes 15.7miles * 1.61 Km /1 mile = 25.3km (Note how the miles in the num & deno cancel and we are left with km  as what the question asked.Keep this principle in mind)
Example #2)
7miles/sec is how many miles / hour?
Soln: 1 hr= 3600 sec In the question given units (sec) are in the denominator of the original measurement, so seconds must be in the numerator of the conversion function.
1 hr= 3600 sec i.e 1=3600/1hr
7miles/sec x 3600 sec/hr =7x 3600 = 25000 miles /hr . (Note the seconds get cancelled)
Example#3)
12 cubic yards = how many cubic feet?
Given: 1 yard= 3 feet . i.e 1 =3feet/1 yard
Therefore 12 yd^3 * (3ft/1yd)^3 = 12 * 3^3 * yd^3 x ft^3 / yd^3 = 12 x 27 ft^3 (Note that the yd^3 gets cancelled out in Num & Deno)
= 324 ft^3 (Ans)
COMING BACK TO YOUR ORIGINAL QUESTION , solution as follows, x mtr/sec= y km/hour
Therefore in terms of x calculate as follows,
xmtr/sec * 60sec/1min * 60min/1hr * 1km/1000mtr
= 18x/5 (note how the mtr,sec & min cancell out in the numerator and denominator giving us what we required)
Answer C



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Re: speed/conversion problem [#permalink]
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14 Dec 2010, 02:10
scorpio7 wrote: Hey guys, was wondering if anyone could offer a way to solve this problem:
If the speed of X meters per second is equivalent to the speed of Y kilometers per hour, what is Y in terms of X? (1 kilometer=1000 meters)
A. 15x/18 B. 6x/5 C. 18x/5 D. 60x E. 3600000x
answer: C. X meters per second > > 3,600X meters per hour (as there are 3,600 seconds in one hour); > 3,600X/1,000=18X/5 kilometers per hour (as there are 1,000 meters in one kilometer). Answer: C. Or if you are not comfortable with above manipulations with variable X then you can assume x to be equal to some #: let x=10. Speed = 10 meters per second > > 10*3,600=36,000 meters per hour > > 36,000/1000=36 kilometers per hour. So, if x=10, then y=36. Plug x=10 into the answer choices, the one which give 36 will be the correct answer: A. 15x/18=150/18<36; B. 6x/5=60/5=12; C. 18x/5=36 correct choice; D. 60x=600; E. 3,600,000x=36,000,000. Answer: C.
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Re: speed/conversion problem [#permalink]
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14 Dec 2010, 20:59
scorpio7 wrote: Hey guys, was wondering if anyone could offer a way to solve this problem:
If the speed of X meters per second is equivalent to the speed of Y kilometers per hour, what is Y in terms of X? (1 kilometer=1000 meters)
A. 15x/18 B. 6x/5 C. 18x/5 D. 60x E. 3600000x
answer: C. Unit conversion is a quick process: \(\frac{X meters}{1 second} = \frac{Y km}{1 hour}\) Replace a km by 1000 m and 1 hour by 3600 seconds \(\frac{X meters}{1 second} = \frac{Y * 1000 meters}{3600 seconds}\) Units get canceled and we are left with: \(\frac{18X}{5} = Y\) Check out my blog post for more examples: http://gmatquant.blogspot.com/2010/11/convertingunitsitsonestepprocess.html
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Re: speed/conversion problem [#permalink]
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14 Dec 2010, 21:42
\((X)(m/s) = (Y)(Km/hr) = (Y)(1000m/60*60s)\) \(Y=(X)*((60*60)/1000) = 3.6X = 18X/5\)



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Re: help solving problem [#permalink]
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25 Dec 2010, 08:01
I think it's \(\frac{18x}{5}\)
Can someone please double check?



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Re: help solving problem [#permalink]
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25 Dec 2010, 08:15
Y=X* 60*60/1000 =>Y= X*36/10 => Y=X*18/5
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HELP for a Gmat prep question [#permalink]
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06 Jan 2011, 08:55
Hello guys,
I can't figure out this problem :
If the speed of x meters per second is eqivalent to the speed of y km per hour, what is y in terms of x ?
5x/18
6x/5
18x/5
60x
3 600 000x
THANKS !!



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Re: If the speed of X meters per second is equivalent to the spe [#permalink]
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30 Sep 2013, 12:48
can some expert give me some questions/links on this forum which involves unit conversions, Spl typical DS question types containing manipulation of speed units to arrive at answers. Have exam in less than a week, any help is appreciated. I tried searching the forum with keyword as "unit conversion" but didnt get what i am looking for
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Re: If the speed of X meters per second is equivalent to the spe [#permalink]
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30 Sep 2013, 20:08
nikhil007 wrote: can some expert give me some questions/links on this forum which involves unit conversions, Spl typical DS question types containing manipulation of speed units to arrive at answers. Have exam in less than a week, any help is appreciated. I tried searching the forum with keyword as "unit conversion" but didnt get what i am looking for Here is a post on conversions: http://www.veritasprep.com/blog/2011/01 ... ndounces/
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Re: If the speed of X meters per second is equivalent to the spe [#permalink]
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01 Oct 2013, 01:13



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Re: If the speed of X meters per second is equivalent to the spe [#permalink]
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25 Mar 2015, 12:56
\(X\frac{m}{s}=X\frac{m}{s}\frac{1 km}{1000 m}\frac{3600 s}{1 h}=X*3.6\frac{km}{h}=X\frac{18}{5}\frac{km}{h}=Y\frac{km}{h}\)
Therefore
\(Y=X\frac{18}{5}\)
Asnwer: C
1:00



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Re: If the speed of X meters per second is equivalent to the spe [#permalink]
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