Okay, how do these units cancel out?

Question

http://img.photobucket.com/albums/v422/Rainbowriver220/2.jpg

I asked this question earlier and everyone told me the answer should be L/mol....but how?

Am I missing some key concept? Please help!

Okay but why does mol have to be on the top?

Answer 1

you have 3 on top and 4 on bottom
that leaves 1 / mol/l
to move the mol/l to the top
you just switch it around
to l/mol

Answer 2

There are 3 factors of mol/L in the numerator & 4 factors in the denominator. Leaving 1 factor of mol/L in the denominator which becomes L/mol, when inverted.

Answer 3

{(mol/lit)^2 mol/lit}/{(mol/lit)*(mol/lit)^3}
{ mol^2/lit^2*mol/lit}/ {mol/lit)*(mol^3/lit^3)}
so its {mol^2/lit^2}/ {mol^3/mol^3}
=lit/mol