10 hrs, 45 min.
8.5 hours
3 hours.
15 hours.
8 hours.
1490
This would be 6.5 hours.
5:45am to 7:30pm is 13 hours and 45 minutes.
6 and 1/2
5-1/2
6.5 hours (6 hours 30 minutes) between 10am and 4:30pm
438
There are 21.5 + 24k hours, where k is an integer.