Bismarck: Math or Chemistry?

Is CC's relationship with Bismarck based On Math Or Chemistry?

It adds up nicely on paper.  Where as, others don't see the connection between CC and Lelouch, they see an immediate connection between her and Bismarck.

Lelouch and CC come from two different worlds! It's an incredible mismatch.
So is it math or chemistry?  It can't be both.

Mathematically CC and Bismarck meet each others needs perfectly. They come from similar spiriitual backgrounds, they like similar things, and connect emotionally.

But C.C.'s connection to Lelouch is mystifying to everyone including the mathematicians.  These two seem to have come together based on chemistry.

Nothing about them adds up. Shes fair and he is dark; shes glitzy and center stage and he is plain and would enjoy working the stage lights or writing the screen play. He is brilliant and she has a learning disability, not smart but talented. She would love to be on the back of a horse and he wants to ride off on a Harley.  Spending time with the guys is his first Friday night choice and she just wants to see him happy no matter what the "friendship" cost.  But they have a very special bond. That's love and that's chemistry.

Math:  Birds of a feather flock together.
Chemistry: Opposites attract.

So what wins out the affections of CC ultimately?  Math or Chemistry?