Guild Wars 2

So as I understand it…

I have a Sup Rune of the Pirate. If I only use 1, I get the first attribute on the list the 10% Magic Find. If I use a 2nd one on another piece of armor, I get the 1st and 2dn attribute 10% Magic Find, and +20 Might Duration.

The question I have is now I have Sup Rune of the Pirate, and a Major Rune of the Noble. The 1st attributes are 10% Magic Find (Pirate), 7% Magic Find (Noble).

So does this give me 17%? Or does the 10% apply and the 7% negated and worthless?

You get both, ie 17%.