# How can I calculate the Yield of this simple reaction? Better yet: what am I asked?

So I have a simple reaction:

$\ce{A(g) <=> B(g)}$

To start with, I had $0.037~\mathrm{mole}$ of $\ce{A}$, and 100 minutes I have $\approx0.03616~\mathrm{mol}$ of $\ce{A}$ and $\approx0.00088~\mathrm{mol}$ of $\ce{B}$.

I reached these values by myself, but now I'm told to calculate the Yield at this point. I'm aware of the equation Fractional Yield = actual yield / theoretical yield. But is it important if the reaction is reversible? In my case it is, would that change the theoretical yield? Or is it always 100%? Is even the fractional yield what I'm asked here? It just says: "calculate the yield of this reaction after 100 minutes have passed".

It's my first problem that includes yield and i would love an explanation. I've searched on google and wikipedia so I know a little bit about it.