There are 10 hours and 45 minutes between 9:30 pm and 8:15am. We can figure this out by counting the hours in between 9:30pm and 8:15am. You would stop at 7:30 am to get 11 hours but 7:30 is not 8:15 is it? So we would need to figure out the additional minutes that we need by first adding 30 minutes to get to 8:00 then another 15 to get to 8:15. When added, 30 plus 15 equals 45.
To conclude, 9:30 pm and 8:15am are 11 hours and 45 minutes apart.
I hope this helped! :-)
