18.5 hours
71/2 hours IF they're both in the same day.
8 hours.
7 hours
2hrs and 30mins
1.5 hours.
9 + 24k where k is an integer.
7 hours and 30 minutes.
7 and a half
4 hours and 15 minutes.
(20.75 - 9.5) hrs = 11.25 hrs = 11 hrs and 15 min
The military normally use the 24 hour clock, so 9:30am would be 0900 hours.
935