19
8 hours.
12
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 pm to 7 am is 12 hours 7 am to 8 am is 1 hours → 7 pm to 8 am is 12 + 1 = 13 hours.
5 hours
From 7 AM to 7:30 PM is a total of 12 hours and 30 minutes. This can be broken down to 12 hours from 7 AM to 7 PM, plus an additional 30 minutes.
On the same day it is 12 hours
From 9:30 pm to 12:00 am is 2.5 hours, then from 12:00 am to 7:00 am is 7 hours. Therefore, the total hours from 9:30 pm to 7:30 am is 2.5 + 7 = 9.5 hours.
12
From 5 AM to midnight is a total of 19 hours. This is calculated by counting the hours from 5 AM to 12 PM (7 hours) and then from 12 PM to midnight (12 hours). Adding those together gives you 7 + 12 = 19 hours.
7 hours 30 minutes.
From 7:30 AM to 9:00 PM is a total of 13.5 hours. This is calculated by counting the hours from 7:30 AM to 7:30 PM, which is 12 hours, and then adding the additional 1.5 hours from 7:30 PM to 9:00 PM.