its recommended 7 to 8 hours
280 hrs
yes there are many phases in sleeping
20
at least 8-10 hours sleep
a 150 pound person sleeping for 8 hours burns 489 calories.
The duration of The Sleeping Child is 1.58 hours.
Between seven and eight on average.
The duration of The Sleeping Dictionary is 1.82 hours.
The duration of While You Were Sleeping is 1.72 hours.
The duration of Sleeping with the Enemy is 1.62 hours.
The duration of The Sleeping Tiger is 1.48 hours.
The duration of The Sleeping City is 1.42 hours.