Explanation

If two trains move on two straight lines with constant speeds, the distance between them changes over time unless the lines are parallel. 

The distance is 10 km at 12:00, 1:00, and 2:00. That is 3 different times. 

For the distance to stay exactly the same for 3 hours with different speeds of 100 km/h and 50 km/h, the trains must keep the same separation forever. 

This can only happen if the tracks are parallel and the trains move in the same direction. Then the faster train gains 50 km per hour but never gets closer because it started 10 km ahead.

If the tracks were non-parallel and intersected, the distance would have to change. It cannot be 10 km at 12, 1, and 2.

Therefore the statement "non-parallel" is false. The tracks must be parallel. 

The angle between parallel lines is 0°.

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Explanation

D's statement directly concerns whether B is lying.

If D tells the truth, B lies; if D lies, B tells the truth.

Therefore, B and D must have opposite identities.

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Explanation

• The chain ultimately loops back through the scholar's own family.
• The phrase "my father's only niece's male first cousin" resolves back to the scholar under normal bilateral family relationships.
• Therefore, the scholar and the male first cousin are the same person.

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Explanation

Two line segments that share an endpoint do not have another intersection.

Segment Alpha → Beta ends at Beta.

Segment Beta → Gamma begins at Beta.

Their only intersection is Beta itself (Kazungula).

If the author instead meant the intersection of the infinite lines extending those segments, that intersection is still Beta, because both lines pass through Beta.

The explanation then switches to a "center of gravity" or "center line" argument. That is not what the question asks. An intersection is a precise geometric concept; it is not a centroid or midpoint.

Nothing in the coordinates places Vatican City near the actual intersection.

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Explanation

Step 1: Find the capitals

Northernmost structural volcanic desert is in Iceland. Capital is Reykjavik.

Lowest point on land is the Dead Sea in Jordan and Israel. Capital is Amman.

Worlds deepest lake is Lake Baikal in Russia. Capital is Moscow.

Step 2: The rule

Count the letters in the capital city name. Then square that number. L squared.

Check:

Reykjavik has 9 letters. 9 squared = 81.

Amman has 5 letters. 5 squared = 25.

Step 3: Apply to Moscow

Moscow has 6 letters. 

6 squared = 36.

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