In everyday, non-mathematical usage then it is preferable to write 1.5 hours.
In mathematics then either expression is acceptable as there is no confusion regarding the number and the unit of measurement is clearly identifiable.
Chat with our AI personalities
45 miles in three hours at 15 miles per hour.
It is: 225/15 = $15 per hour
2 hours
3 hours 15 minutes minus 1 hour 35 minutes = 1 hour and 40 minutes
Yes, to be precise: 7.25 HOURS is the same as 7 hours and 15 minutes. 7.25 hours is 7 hours plus 0.25 hours. In words, 0.25 hours is one-fourth of an hour, and one-fourth of an hour is equal to 15 minutes.