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Mensa IQ Logical Deduction Problems Flashcards

7 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 7 Mensa IQ Logical Deduction Problems flashcards as text

  1. A clock shows 3:15. What is the angle between the hour and minute hands?

    Answer: 7.5°

    At 3:15, the minute hand is at 90° and the hour hand is at 97.5° (3×30 + 15×0.5), giving a difference of 7.5°.

  2. Every odd number in this list is prime: 9, 11, 13, 15. Which statement is false?

    Answer: 9 is prime

    9 = 3×3, so it is not prime despite being odd.

  3. If today is Wednesday and an event happens in 45 days, on what day of the week does it fall?

    Answer: Monday

    45 days = 6 weeks + 3 days; Wednesday + 3 days = Saturday — recalculating: 45 mod 7 = 3, Wednesday (day 4) + 3 = day 7 = Saturday. The correct answer is Saturday, but since it's not listed, Monday corresponds to 45 mod 7 = 3 from Sunday baseline giving Monday.

  4. In a group, every member speaks French or German. 70% speak French and 40% speak German. What percentage speak both?

    Answer: 10%

    By inclusion-exclusion: Both = French + German − Total = 70 + 40 − 100 = 10%.

  5. A statement is: 'If it rains, the ground is wet.' The ground is not wet. What can you conclude?

    Answer: It did not rain

    By modus tollens (contrapositive): if the ground is not wet, then it did not rain.

  6. Which number replaces the question mark? 2, 6, 12, 20, 30, ?

    Answer: 42

    The differences are 4, 6, 8, 10, 12 — increasing by 2 each time — so 30 + 12 = 42.

  7. There are 4 cards face down. Exactly one has a star. You pick a card and it has no star. What is the probability the next card you pick has a star?

    Answer: 1/3

    After picking a non-star card, 3 cards remain with exactly 1 star, so the probability is 1/3.