6 hours.
7.5 hours
7.5 hours
It is five hours.
13.5
4 hours and 35 minutes.
8 hours and 55 minutes.
8:30 AM to 1:00 PM is four and a half hours.
5 hrs, 15 mins
8 and 1/2
(5.5+24k) hours where k is an integer.
945 pm to midnight is 2 hours, 15 minutes. Midnight to 830 am is 8 hours, 30 minutes. The total is 10 hours, 45 minutes.