It is 4(1 + 3k) hours where k is any integer.
6 and 1/2 hours
6
About 6 1/2 hours.
6
6 to 6 and 1/2 hours
6 to 6 and 1/2 hours
2:15am to 6:00pm is 15 hours and 45 minutes. 2:15pm to 6:00pm is 3 hours and 45 minutes.
6 and 1/2 hours
approximately 6 1/2 hours.
6 1/2 hours
130/60 = 13/6 = 2 and 1/6 hours or 2.16666 in decimal
between 6 and 6 and 1/2 hours