PDR Stacking

Ok, so I have a few questions about PDR
1. Does it stack on multiple lines of a weapon?(ie would a dagger with 30% PDR on 1st line and 15% PDR on 2nd line give 45% PDR?)
2. Does it stack on multiple weapons?(15% PDR dagger+15% PDR katara=30% PDR?)
3. Do weapon and monster book stack?(15% PDR from monster book+15% PDR dagger=30% PDR?)
4. How much would ignore 30% PDR increase your DPS on a boss with 50% PDR, compared to having no PDR? Would it be more effective exponentially?(if I had 50% ignore PDR, would it be exponentially better than 30% PDR?)

This goes under Q&A brah.

1. Yes
2. Yes
3. Yes
4. Obviously it's better to have more ignore PDR, it depends on what you're ignoring though in relation to %boss.

This goes under Q&A brah.

1. Yes
2. Yes
3. Yes
4. Obviously it's better to have more ignore PDR, it depends on what you're ignoring though in relation to %boss.

alright thanks.