Is it normal for levels to take 4 hours questing with only 3 chars?

[Boylston]

Either i am just really shitty at this... or i'm questing in wrong areas

lvl 47 in tanaris/ferals

quests take like 20 mins each and only give like 5k exp >_<

No, it's not normal. You are doing something wrong.

It all depends, really. Are you doing a bunch of collection quests in there? Are you following a leveling guide? I highly recommend using a questing guide and questing 1-2 levels "ahead" of it, since you have multiple people and can probably kill +2/3 mobs with speed and ease.