It is (1.5 + 12*k) hours, where k is an integer.
10 and a half hours
The time from 7:30 to 5:30 is 10 hours. This is calculated by counting the hours from 7:30 AM to 5:30 PM.
530 minutes is 8 hours, 50 minutes.
1460
7.75 hours
This is equivalent to 16 hours.
1360
9
This is equivalent to 16 hours.
Ten hours.
Time = distance / speed = 530 / 75 = 7.0666.. hours = 7 hours and 4 minutes.
4.5