12am to 4pm is 16 hours.
12 hours
18 hours
21
17
4
7
21
10
113 hours
72 hours from Sunday at 12am would be Wednesday at 12am. This is because there are 24 hours in a day, so three days would be 72 hours. Starting at Sunday at 12am, you would count 24 hours for each day, bringing you to Wednesday at 12am.
5 hours + 12 hours is 17 hours