11 hours
one hour
how many hours is 6:30pm to 6:30am
4 and 1/2
That would be ten and one half hours.
7 hours and 30 minutes.
From 8PM to 1PM (the next day) is 17 hours.
9 + 24k where k is an integer.
4 hours and 15 minutes.
From 9am to 6:30pm is 9 hours and 30 minutes.
2 hours
3 hours