5.5 hours. (30 minutes is half an hour, expressed as 0.5hrs, or every 0.1hrs is 6.0min.)
It is: 4.5 hours
2.5
2.5 hours
It is 1.5 hours
Everything before the decimal is hours. Everything behind multiplies with 60. 3 hours and (0.5x60=30) 30 minutes.
You write "six and a half hours" as 6.5 hours. Mathematically, that's the correct way to represent a number with a decimal point. So, there you have it - no need to complicate things!
III hours, XXX minutes
First you divide by 60 to find the hours. In this case, you do 1800/60 and get 30. There is no decimal part or remainder and so there will be no minutes. Therefore, in 1,800 minutes, there is exactly 30 hours.
To convert the decimal part of a hour to minutes multiply by 60. So 13.5 hours = 13 h 30 minutes.
7 h. 30 min.
450 minutes.