Okay, start with the basic equations for capacitance and resistance;

[tex]R = \frac{V}{I}[/tex]

[tex]C = \frac{Q}{V}[/tex]

Now using the fact that current is the rate of flow of charge ([itex]I = \frac{Q}{t}[/itex]) can you eliminate the current (I) from the first equation?

No. I have never been shown this equation beofre either. Thanks for all your help, but I think it would be best if I went and asked tomorrow, because I think he may have made a mistake.