It takes two hours for a person to travel from gujarat to Arunachal pradesh as there is a gap of 30 0 longitude between them.
hence, with increment of 10 time is increased by 4 min.
SO, 10 = = = = = = = = 4
300 = = = = = = = = ? (TIME)
hence, by unitary method,
TIME = 120 min
So, TIME = 2 hours
- - - - - - - - - - - - hence proved
therefore, the time taken to travel from gujarat to Arunachal pradesh or vice versa the time gap is 2 hours.