Give reasons for the following:

The difference between I.S.T. and the G.M.T. is 5 hours and 30 minutes.

The difference between longitudes of I.S.T. and the G.M.T. = 82 1⁄2°

Since, the difference of 1° in longitude = a difference of 4 minutes

Therefore, for difference of 82 1⁄2°, the difference in time = 4 x 82 1⁄2 = 330 minutes = 5 hrs 30 min.