1.81 hrs
4 minutes 22 seconds.
1,243.6 seconds to cover 19 miles at 55mph
18/55 = 0.327 (to 3 decimal places).The answer is therefore 0.327 hours (to 3 decimal places).(We must assume you meant to write 55mph in your question and I will amend it so).
52.8 seconds to travel 4,260 feet @55mph
At 55mph about 10 hours
36 minutes.
33mins
Two hours 3 minutes.
10 hours 21 minutes.
22 minutes 54.5 seconds.
29 hours 5.5 minutes.
1 hour and 1 minute.
7 hours 49 minutes.
1 hour 16 minutes.
0.8 hours or 48 minutes
9.50909 hours (or 9:30:32.7) 523 / 55 = 9.50909