Transformer - working out the secondary voltage

Hi
I'm a little rusty on my transposition of formulas.

vp/vs = np/ns is the gerneral formula for transformers. I rewritten it in order to get vs on it's own. Hence it be Np/ NsX Vp. However the answer I get doesn't match the one on the answer sheet until I flip it upside down to get Ns X Vp / Np. Why do I need to flip it upside down? I seem to vaguely remember this from school.

hi,
Its in a Ratio not a Divide, ie: Vp:Vs :: Np:Ns

So, Vp/Np = Vs/Ns .......... Vs= (Vp*Ns)/Np

Let's do it in baby steps: Vp/Vs = Np/Ns solve for Vs

#1. Divide both sides by Vp
.......1/Vs = Np/(NsVp)
#2 flip both sides
.......Vs = (NsVp)/Np

Thanks alot keepitsimplestupid. I love the way how you phased it lol. But I learn in baby steps lool