There are 6 lots of 10 minutes in the hour, so she makes 48 cups of coffee
======================
To find out how many chunks or lots of 10 minute periods there are in an hour, simply divide 60 over 10
60/10 = 6
So there are 6 groups of ten minute periods in the hour
Now multiply this by 8. This is because she makes 8 cups for each ten minute period
8*6 = 48