If you have used up all of your 14 hour on duty time, how many hours would you regain after an 8 hour break in the sleeper berth?

A You will still have no hours remaining.

explanation

Eight hours of sleeper berth time:
You may also use the sleeper berth to extend the 14 hour limit. Any period in the sleeper berth of at least 8 consecutive hours will not count as part of the 14 hours, and, therefore, would allow you to extend the time during which you could use your maximum 11 hours of driving.