If Greenwich Meridian Time is 12 noon, then what will be the time at 45° East…

Concept: Earth completes one full 360° rotation in 24 hours, so every 15° of longitude corresponds to a 1-hour difference in local time (equivalently, every 1° of longitude corresponds to 4 minutes of time). A location east of the Prime Meridian (0° at Greenwich) has a local time ahead of Greenwich Mean Time (GMT); a location west of it has a local time behind GMT.

Application:

1. The given position is at 45° East longitude, measured from the Prime Meridian at Greenwich.

2. Time difference = 45° × 4 minutes per degree = 180 minutes = 3 hours.

3. Since the position lies east of Greenwich, this 3-hour difference is added to the Greenwich time, not subtracted.

4. Local time = 12:00 noon (Greenwich time) + 3 hours = 3:00 p.m.

Cross-check: Cross-check with the equivalent 15°-per-hour rule: 45° ÷ 15° = 3 hours, the same adjustment obtained above, confirming a 3-hour eastward shift.

Therefore, the local time at 45° East longitude is 3 p.m.