7 hours and 30 minutes.
one
22
16 + 24k hours where k is any integer.
11am to 12 is 1 hour 12 to 5pm is 5 hours → 11am to 5pm is 1 + 5 = 6 hours
72
On the same morning there are 3 hours from 8am to 11am
3 hours.
2 hours
1.5 hours.
19 hours
12 hours
20