TROLL hunter!

[Kazita]

ADDON:
#showtooltip Rapid Fire
/cast Call of the Wild (Ferocity pet)
/cast Roar of Recovery (Cunning pet, might not want to use this with Rapid Fire.)
/cast Berserking
/cast Rapid Fire
/use Potion of the Tol'vir

Berserking- cast 20% faster for 10sec
Rapidfire - cast 50% faster for 20sec
Does that mean if i use ber and rapid at the same time it will cast 70% faster ?

[Deleted]

The correct answer to that question would be no, but hang on.
It is 40% (or 50% when glyphed) for rapid fire and 20% for berserking (haste increase).
This means 1.4*1.2 = 1.68 = 68% speed increase.
Or glyphed: 1.5*1.2 = 1.8 = 80% speed increase

So they don't stack, they individually increase your haste.

Yes, you can use them at the same time for the 68%/80% speed increase (not 50%+20%, alot of people make mistakes with adding percentages). They also 'stack' with Bloodlust/Timewarp/Heroism and other haste increasing buffs.
You can check stuff like this yourself btw, by watching your casting speed change after you enabled the buffs.