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?

5x/18

6x/5

18x/5*

60x

2,600,000x

They're trying to trick you by giving you inconsistent units.

So perform dimensional analysis to get the same units on both sides and then solve for Y.

Ok I tried typing it out here, but it's just to time consuming to type out formula's here. Eaiser to use MS Equation Editor:

best way to solve problems like this one - in which there are UNDETERMINED VARIABLES (meaning that not only are they unknown, but you actually CAN'T find specific values for them) - is to plug in sample numbers for the variables, and solve the problem with the more specific numbers in place.

so:
try x = 2
then we have 2 meters per second
which is 2 * 3600 = 7200 meters per hour (since there are 3600 seconds in an hour)
which is 7200 / 1000 = 7.2 kilometers per hour (since there are 1000 meters in a kilometer)
therefore:
if x = 2, then y = 7.2

now all you have to do is plug x = 2 into the answer choices, and see which of the choices gives 7.2.
a = 10/18
b = 12/5
c = 36/5 = 7.2
d = 120
e = 5,200,000

therefore, answer = c