The time at the Greenwich Meridian is 10:00 am. What would the time at 30ºE be?

Analyze the question: Greenwich (0°) is at 10:00 am. We need the time at 30°E.

Concept: The Earth rotates 360° in 24 hours, so:

• 360° ÷ 24 hours = 15° per hour
• 1° = 4 minutes
• Places east of Greenwich are ahead (time is later).
• Places west of Greenwich are behind (time is earlier).

Solution:

1. Longitude difference = 30° − 0° = 30°
2. Time difference = 30° ÷ 15° per hour = 2 hours
3. 30°E is east of Greenwich, so we add 2 hours:

10:00 am + 2 hours = 12:00 noon (12:00 pm)

Checking the options:

• A (8:00 am) would be correct for 30°W, not 30°E.
• B (8:00 pm) is wrong because it is the wrong direction and the wrong period of day.
• C (12:00 am) means midnight, which would be 14 hours away, so it is wrong.
• D (12:00 pm) means noon, which matches our working.

Exam tip: Remember "East is Early... no, East is Ahead (Least → Add)." A simple way to recall it is: "East = Add, West = Withdraw." Also remember that 12:00 am is midnight and 12:00 pm is noon, because WAEC often tests this to catch careless students.