60 minutes = 1 hour so 400 min = 400/60 = 6.66... hours. Simple!
0 hours are in 20 min an hour is 60 min
400
8 hours, 20 minutes
610 min / 60 = 10.167 hours.
2 hours
5 hours, 50 minutes
320 min = 51/3 hours = 5hours 20minutes
5.5 hours.
2 hours
1.95 hours.
3 hours