Two towns, A and B, are on the international dateline. What will be the distance between the two towns if town…

Analyze the question: Both towns lie on the International Date Line (180° longitude), so they are on the same meridian. The distance between them is therefore found from the difference in latitude alone.

Concept: Along a meridian (a great circle), 1° of latitude ≈ 111 km. (This comes from the Earth's circumference of about 40,000 km ÷ 360° ≈ 111 km.)

Solution:

1. Difference in latitude: both towns are in the Northern Hemisphere, so 40° − 10° = 30°
2. Distance = 30 × 111 km = 3,330 km

If you use 1° ≈ 111.1 km, you get about 3,333 km, which is still closest to 3,330 km.

Answer: The distance is 3,330 km, which is option C.

Tip: For two places on the same meridian, subtract the latitudes if they are on the same side of the equator, and add them if they are on opposite sides. Then multiply by 111 km. If they share the same latitude instead, use the formula 111 × cos(latitude) × difference in longitude. Watch the hemispheres (N or S) carefully, because that is where students often lose marks.