There are 11 hours between 6 am and 5:30 pm.
3 hours and 15 min
7.75 hours
This is equivalent to 16 hours.
The parameters you cite contain eight hours and 30 minutes.
Ten hours.
This is equivalent to 16 hours.
6 hours.
9 hours, 45 minutes
8 hours and 30 minutes.
(8.5+24k) hours where k is an integer.
(11+24k) hours where k is an integer.