Question

Calculate the time at Durban (longitude 30°E) when the time is 7.00 a.m. at New York (75°W).

Answer 1

The longitudinal difference between Durban and New York is 30° + 75° = 105°, so the time will be 105 × 4 = 420 minutes ahead from New York. There is a difference of 420 minutes or 7 hours, or 2 p.m.