Mensa IQ Odd One Out Puzzles Flashcards

Which does NOT belong? Quartz, Obsidian, Granite, Diamond

Answer: Obsidian

Quartz, Granite, and Diamond are all crystalline minerals or rocks with an ordered atomic structure, while Obsidian is a volcanic glass with a non-crystalline (amorphous) structure.

Which number is the odd one out? 16, 25, 36, 48, 64

Answer: 48

16, 25, 36, and 64 are all perfect squares (4², 5², 6², 8²), but 48 is not a perfect square.

Which word does NOT belong? Stalagmite, Stalactite, Speleothem, Stalwart

Answer: Stalwart

Stalagmite, Stalactite, and Speleothem are all geological formations found in caves, while Stalwart means loyal and hardworking and has no geological meaning.

Which instrument is the odd one out? Violin, Cello, Harp, Viola

Answer: Harp

Violin, Cello, and Viola are all bowed string instruments belonging to the viol family, while Harp is a plucked string instrument of a different family.

Which sequence is the odd one out? 2-4-8, 3-6-12, 5-10-20, 4-8-13

Answer: 4-8-13

In 2-4-8, 3-6-12, and 5-10-20 each term doubles the previous one (×2), but in 4-8-13 the third term adds 5 instead of doubling.

Which word does NOT belong? Epistle, Memoir, Sonnet, Haiku

Answer: Memoir

Sonnet and Haiku are poetic forms, and Epistle can also be a type of poem or verse letter, while Memoir is a prose narrative recounting personal experiences.

Which does NOT belong? Semaphore, Morse Code, Braille, HTML

Answer: HTML

Semaphore, Morse Code, and Braille are all non-verbal encoding systems designed for direct human communication, while HTML is a markup language for structuring digital documents.