Answers:
I believe it depends so much of the character and to what tempo the human being is used to...and also depends of the time when it is best for that party to progress to bed. For ex. the best suiting time for me is to budge to bed at 10 PM and after I can rouse up at 6 AM efficiently...but if I shift to bed at around 11-midnight, I will own a BIG problem to bring up even at 9 or 10 AM ;)
So yes, possibly 8 hours is the best number...but as said, sometimes not even 10-11 hours is adequate :o
On average, 8 hours of sleep.
u can live on 4-6 a dark. but 8 is reccomended.
Nine hours, they should hold more sleep than the average full-grown, because they are still developing.
Teens do stipulation an hour more because of growth...
However.. it have be proven that if a teen is sleeping too much that it can be drug related.
I am not accusing your son.. but fairly informing you if you see too much sleeping going on.
The average is 6-8 hours
but instinctively I thought they sleep adjectives the time