9 hours.
There are 9 hours between 630 am and 930 am.
The shortest possible interval with that description is nine (9) hours. It can be 9 plus (any multiple of 12) hours.
Well, honey, if you can't count the hours between 6:30 am and 3:30 pm, then we've got bigger problems on our hands. But since you asked, that's a total of 9 hours. Math doesn't have to be a mystery, darling.
330 hours = 13.75 days
330/60
9 hours.
330 minutes is 5 hours and 30 minutes.
7 hours
5.5 hours.
7 and a half hours
10.5 hours