Question

Calculate the longitude of a place where the local time is 6.00 a.m. when the time is 9.00 p.m. at New Delhi on longitude 77° E. 

Answer 1

The time difference between the required place and New Delhi is 6 + 9 = 15 hours, so the time in minutes = 15 × 60 = 900 minutes. So the longitudinal difference is 900/4 = 225°. So the place will be in the west at 225° – 77° = 148° W.