It is possible to gain thirty attribute points beyond the 170 points you receive for leveling up to twenty. I know one way is the quest you get in Destiny's Gorge that leads to the Forgotten Sariss Yassith in Skyward Reach who in turn gives you a quest that leads to Siliss Yassith in the Arid Sea who gives you 15 attribute points. Does anyone know how to receive the remaining 15 attribute points?

First you to do one of the "... Path" quests, such as "Warrior's Path". You don't need to change your secondary at the end.

Next talk to Varyi (I think, the NPC next to the storage NPCs) in Droknar's Forge. She will give you the second attribute quest.

where do u get the ".....path" quests?

I never did a secondary change quest and I still got both of the Attribute quests.

You get the ...Path quests from ghosts in the three explorable outposts in the desert - Hero's Audience, Destiny's Gorge or Seeker's. I believe you have to be ascended or level 20 for the quests to be offered.

You must have done it a while ago. I didn't either, with my first character. I think they changed this in an update, though, because it made me do one for my second and third ascended characters.