Ten hours. Subtract the smaller number from the larger. Then subtract the remainder from 12.
73 hours.
from 7:30 am till 7:00 pm it is 11 hours and a half.
10 - 3 = 7 hours.
13 + 24k hours where k is an integer.
7 and a half hours
The time from 8 AM to 7 PM is 11 hours. This is calculated by counting the hours from 8 AM to 12 PM (4 hours) and then from 12 PM to 7 PM (7 hours), which totals 11 hours.
7 hours and 30 minutes
19
From 1 PM to 7 PM is a duration of 6 hours. You can calculate this by subtracting 1 from 7, which gives you 6.
There are 17 hours between 2 am and 7 pm.
12
It is seven hours from 9 AM to 4 PM.