Calculate the distance between town Y which is on latitude 40° N and town Z which is on latitude 10°S

Analyze the question Towns Y and Z are on the same meridian (the question gives only latitudes, so we assume this). Y is north of the equator and Z is south of it. We need the distance along the meridian between them.

Concept

• One degree of latitude is about 111 km on the Earth's surface.
• Because Y and Z are on opposite sides of the equator, add their latitudes. If they were on the same side, you would subtract.

Solution

Step 1: Find the angular difference. 40° N + 10° S = 50°

Step 2: Convert to distance. Distance = 50 × 111 km = 5550 km

Answer: D. 5550 km

Tip: Use this rule in latitude questions:

• Same hemisphere (both N or both S): subtract the latitudes.
• Opposite hemispheres (one N, one S): add the latitudes. Then multiply by 111 km. Options like 1110 km (10°) and 4440 km (40°) are traps for students who use only one of the latitudes.