The 'road' wheels for my mountain bike are setup.....a triple with a 9-speed rear that yields about 25 effective gears.
What I did was use a cassette thats designed to pick-up where the previous chainring left off...
The answer is yes, your bike does have 27 gear ratios...no 2 are exactly alike although many are very close.
I didnt know I was an ignoramous......Oh, well.....