Just going over old queries and found your questions, Bill. I agree (or interpret) that one duplex is all that is required..no matter how many sinks, as long as it is within 3'of each sink's edge. Your workshop instructor was mistaken. All that is necessary is that someone can plug in some bathroom appliance without using an extension cord, since the appliance cords can't be longer than 3'.
In reality, the Code wording results in two receptacles (one for each sink), since the wall space between the sinks is usually pre-empted by the mirror.
[This message has been edited by Elzappr (edited 01-15-2002).]