Problem Solving

swerve wrote: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. \(\frac{5x}{18}\)
B. \(\frac{6x}{5}\)
C. \(\frac{18x}{5}\)
D. \(60x\)
E. \(3600000x\)

The OA is C

Source: GMAT Prep

We have \(X\) meters per second = \(Y\) kilometers per hour

=> \(X\) meters per second = \(Y\) * (1,000/3,600) meters per second

\(X\) = \(Y\) * (5/18)

\(Y\) = \(18X/5\)

The correct answer: C

Hope this helps!

-Jay
_________________
Manhattan Review GMAT Prep

Locations: GRE Manhattan | ACT Tutoring San Antonio | GRE Prep Courses Boston | Houston IELTS Tutoring | and many more...

Schedule your free consultation with an experienced GMAT Prep Advisor! Click here.

swerve wrote: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. \(\frac{5x}{18}\)
B. \(\frac{6x}{5}\)
C. \(\frac{18x}{5}\)
D. \(60x\)
E. \(3600000x\)

The OA is C

Source: GMAT Prep

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