If the speed of X meters per second is equivalent to the speed of Y ki

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=1000meters).

\(y*\frac{kilometers}{hour}=x*\frac{meters}{seconds}\)

\(y*\frac{1\;kilometer}{1\; hour}*\frac{1000 \;meters}{1 \;kilometer}*\frac{1\; hour}{3600 \;seconds}=x*\frac{meters}{seconds}\)

\(y*\frac{1000 \;meters}{3600 \;seconds}=x*\frac{meters}{seconds}\) --------> \(y=\frac{3600}{1000}*x=\frac{18}{5}*x\)

Answer C

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

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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Bunuel, is this a word problem or what tipe of problem is?
Do you have a link to find more of these problems, please?

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)

We need to find an equation with x in the answer...
convert all measurements so they are alike (i.e. convert km to m, seconds to hours, etc)

Speed = x/t
x meters/second
(3600) x meters/hour

Speed = y/t
y KM/hour
Speed = y(1000m)/hour

y(1000meters)/hour = (3600) x meters/hour

y(1000)/1hour = x(3600) / 1 hour
y(1000) = x(3600)
y = 3.6x

Answer: C. 18x/5

x meters in 1 second i.e

\(\frac{x}{1000}\) Kms in 1 Second i.e

\(\frac{x}{1000}\) Kms in \(\frac{1}{60}\) Minutes i.e

\(\frac{x}{1000}\) Kms in \(\frac{1}{3600}\) Hour i.e

\(\frac{x}{1000} * 3600\) in 1 Hr = Y

\(y = \frac{18x}{5}\)

Answer = C

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)

In order to avoid the confusion in conversions, lets write this equation in its simplistic format.

\(x * \frac{Meters}{Second} = y * \frac{Kilometers}{Hour}\)

\(x * \frac{Meters}{Second} = y * \frac{Kilometers}{Hour} * \frac{(1000) Meters}{(1) Kilometer} *\frac{(1) Hour}{(60 * 60) Seconds}\)

Cancelling out the units - Kilometers and Hours on the R.H.S.

\(x * \frac{Meters}{Second} = y * \frac{(1000) Meters}{(3600) Seconds}\)

\(x * \frac{Meters}{Second} = y * \frac{(5) Meters}{(18) Seconds}\)

Lets take values in terms of y:

\(y * \frac{Meters}{Seconds} = x * \frac{Meters}{Second}* \frac{18}{5}\)

Which means:

\(y = \frac{18x}{5}\)

Hence, the answer is C

Hope you LIKE this solution, if YES, 1 Kudos Please

Hi All,

This question can be solved in a couple of different ways; you can use unit conversions or you can use TEST IT:

We're asked to convert X meters/second into Y kilometers/hour....

If X = 2, then...

2 meters/second =
120 meters/minute =
7200 meters/hour =
7.2 kilometers/hour

So we need an answer that equals 7.2 when X = 2

Plugging 2 into each of the answers gives us...

A) 10/18 = 5/9
B) 12/5 = 2.4
C) 36/5 = 7.2
D) 120
E) 7,200,000

Final Answer:

GMAT assassins aren't born, they're made,
Rich

There are 3,600 seconds in an hour and 1,000 meters in a kilometer. So, let’s convert y kilometers/hour to meters/second:

We can start by converting y kilometers to meters.

y kilometers = 1,000y meters

Next we can convert 1 hour to seconds.

1 hour = 3,600 seconds

Thus, y km/hr can be expressed as 1,000y/3,600 m/sec, or 5y/18 m/sec, after it’s simplified.

Since our two rates are equal, x = 5y/18. We need to solve this equation for y.

18x = 5y

18x/5 = y

Answer: C
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Check other Conversion problems to practice in Special Questions Directory.
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Y km/hr = Y 1000 / 60*60 m/s = 5Y/18 m/s = X m/s
Y = 18X/5

IMO C

When converting meters per second to kilometers per hour we multiply by 18/5.

When converting kilometers per hour to meters per second we multiply by 5/18.

Answer is C: 18x/5.
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Hello folks,

How can't we calculate from x like:

x*(1000/3600) = Y i.e final result is B)

I fell in the trap b/c i started converting on X side and not Y, so i found 18x/5 ..

I don't understand why it does not work if we convert from X and not from Y ...

Thanks a lot for your help !

Hi blanchif

I fell into the same trap and found a way to avoid it, you can proceed with the following reasoning :

We know that xm/s=yk/h
We want y in terms of x, and here is where the trap is set :
we have to work only on the y side as we want y in terms of x. In other words, we need to convert y in terms of x. For example x is in seconds so we need to turn y's hour into seconds which becomes 3600 seconds

xm/s=1000y/3600
x=5y/18
therefore y = 18x/5


EDIT:

Just to clarify why we can't do it the other way around: It's because here we want one hour into seconds, but you can't turn one second into hours.

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