n-tier question

I'm going to sound stupid, and I apologize, but the concept of n-tier is new to me, and I'm an old dog, so its hard to teach me new tricks.

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I am completely re-designing an ongoing project from the ground up according to n-tier concepts.�  I have decided to go with a simple 3 tier design (combining BLL & DAL) to begin with.�  I would imagine if coded correctly it wouldnt be all that difficult to switch to 4 or� 5 tier (fingers crossed).

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My question is this.�  I am returning a table to the presentation layer from a class method in the� BLL/DAL layer.� Is this ok?�  Does this provide seperation of logic?� 
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