Hi ashleyjan,

This question is built around what's called "unit conversion"; you're asked to convert meters per second into kilometers per hour. You can do this either with algebra or with a tactic that let's you TEST values.

Here's the algebra:

60 seconds per minute
60 minutes per hour
1000 meters per kilometer

So, x meters per second = 60x meters per minute = 3600x meters per hour = 3.6x kilometers per hour = y

Thus...

y = 3.6x which can also be written as y = 18x/5

Here's the TEST values:
x = 1

1 meter per second = 60 meters per minute = 3600 meters per hour = 3.6 kilometers per hour = y
Notice how similar this is to the "math" approach?

y = 3.6x

Moving forward in your studies, you need to be comfortable converting lots of different types of units because the GMAT will require you to do so.

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