830 930 1030 1130 1230 130 230 330 7 hours
18½ hours
10:30 to 3:30 is five hours.
That is 2 hours and 1 hour = 60 minutes 2 x 60 = 120 minutes
It is 4 hours.
18½ hours
5 and a half
it is 1 hour 30 mins = 1½ hours.
7
eight 17:30 - 09:30 = 08:00
9 hours and 30 minutes.
Eight and one half hours.