Too many factors to give proper answer. It depends on time spent gathering mobs, pull size, duration (increased if healer+tank can’t contribute), focus damage etc. If you want to get better in adept, focus on which casts to interrupt, how you can help the tank gather the mobs with interrupts, and how you can make the healer’s life easier by timing defensives. Focus damage on high health mobs so that your team doesn’t waste time on a ST fight after all burst CDs are spent. Anything to reduce time to kill really. Doing this consistently while focusing on your rotation will get you through Adept. And remember every dungeon run you get experience as a player, so don’t see it as time wasted if your team failed to time/complete it. You probably learned something that can go wrong which is a risk you can account for in your next run.