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Mensa IQ Odd One Out Puzzles Flashcards

6 cards from real MENSA practice questions. Tap to flip, then mark Knew It or Still Learning — missed cards come back until you master them.

Read the first 6 Mensa IQ Odd One Out Puzzles flashcards as text

  1. Which number does NOT belong in this group: 2, 3, 5, 7, 9, 11, 13?

    Answer: 9

    All other numbers are prime (divisible only by 1 and themselves), but 9 = 3 × 3 is composite. It is the only number in the set that has factors other than 1 and itself.

  2. Which shape does NOT belong: circle, oval, sphere, square?

    Answer: Square

    Circle, oval, and sphere are all based on curves with no straight edges or angles. A square has straight sides and right angles, making it fundamentally different from the curved shapes.

  3. Which number is the odd one out: 1, 4, 9, 15, 25, 36?

    Answer: 15

    1, 4, 9, 25, and 36 are all perfect squares (1², 2², 3², 5², 6²). 15 is not a perfect square — it cannot be expressed as any integer multiplied by itself.

  4. Which word does NOT belong: Dog, Cat, Fish, Chair, Bird?

    Answer: Chair

    Dog, cat, fish, and bird are all living creatures (animals). Chair is an inanimate piece of furniture, making it categorically different from the rest.

  5. Which number does NOT fit the pattern: 8, 27, 64, 100, 125?

    Answer: 100

    8=2³, 27=3³, 64=4³, 125=5³ are all perfect cubes. 100 is not a perfect cube (4.64³ ≈ 100), making it the odd one out. 100 is actually 10², a perfect square.

  6. Which figure does NOT belong: triangle, square, pentagon, circle, hexagon?

    Answer: Circle

    Triangle, square, pentagon, and hexagon are all polygons — closed figures with straight sides. A circle has no straight sides or vertices, making it fundamentally different from the polygons.