Mixed Deck — All MENSA Topics Flashcards

Which 3D solid has exactly one curved surface and one flat circular face... actually two: which has one flat face and one curved surface?

Answer: Cone

A cone has a single circular flat base and one continuous curved surface.

All writers are readers. No readers are illiterate. Therefore:

Answer: No writers are illiterate

All W→R and No R→I (Celarent) → No W→I.

A pattern of shapes is shown: ○ □ △ ○ □ △ ○ □ △. What is the 11th shape?

Answer: A. ○

The pattern repeats every 3: ○□△. Position 11: 11÷3 = 3 remainder 2... wait, 3×3=9, 10th=○, 11th=□. Hmm: position 1=○, 2=□, 3=△, 4=○... 11 mod 3 = 2, but we use 1-indexing: if remainder is 2, it's the 2nd in the pattern = □. But let me recount: 1=○, 2=□, 3=△, 4=○, 5=□, 6=△, 7=○, 8=□, 9=△, 10=○, 11=□. The 11th shape is □.

Which figure is the odd one out: a circle, an oval, a square, and an ellipse?

Answer: Square

The square has straight edges and corners while the others are curved closed loops.

A train travels 60 miles in 45 minutes. What is its speed in miles per hour?

Answer: 80 mph

45 minutes is 0.75 hours, so 60 / 0.75 = 80 mph.

What is 15% of 80, plus 25% of 40?

Answer: 22

15% of 80 is 12 and 25% of 40 is 10, totaling 22.

A sequence shows: [Circle with 1 dot inside] → [Circle with 2 dots inside] → [Circle with 3 dots inside] → [?]. What comes next?

Answer: Circle with 4 dots inside

Each figure adds one dot inside the same circle shape, so the next has 4 dots.

Complete the series: 1, 4, 9, 16, 25, ?

Answer: 36

The series consists of perfect squares: 1²=1, 2²=4, 3²=9, 4²=16, 5²=25, 6²=36.

If no birds are mammals and all sparrows are birds, then:

Answer: No sparrows are mammals

Sparrows are birds, and no birds are mammals, so no sparrows are mammals.

A says: 'B's father is the only son of C.' C is A's father. How is B related to A?

Answer: Niece or Nephew

C's only son is A himself (A's father = C); so B's father is A — B is A's child (son or daughter), making A B's parent. But the question asks how B is related to A: B is A's child. Reversing: A is B's parent, so B is A's son or daughter.

A square has an area of 144. What is its perimeter?

Answer: 48

The side is √144 = 12, so the perimeter is 4 × 12 = 48.

A calendar shows: Monday=3, Tuesday=4, Wednesday=5... continuing this pattern, what number does Sunday have?

Answer: B. 9

Monday=3, Tuesday=4, Wednesday=5, Thursday=6, Friday=7, Saturday=8, Sunday=9.

Find the missing term: 1, 6, 15, 28, ?

Answer: D. 45

Differences: 5, 9, 13 — increasing by 4. Next difference = 17. So 28 + 17 = 45. (Hexagonal numbers: n(2n-1))

PEDAGOGY : TEACHING :: JURISPRUDENCE : ?

Answer: Law

Pedagogy is the theory and practice of teaching; jurisprudence is the theory and philosophy of law.

A pipe fills a tank in 4 hours; another pipe empties it in 6 hours. If both are open, how many hours to fill the tank from empty?

Answer: 12

Filling rate = 1/4 per hour; emptying rate = 1/6 per hour; net = 1/4 − 1/6 = 1/12 per hour; time = 12 hours.

In a matrix puzzle, each cell contains a shape that is the XOR (symmetric difference) of the shapes in the same row's first two cells. Row 1: circle, square → circle-with-square-cutout. Row 2: triangle, circle → triangle-with-circle-cutout. Row 3: square, triangle → ?

Answer: Square with triangle cutout

The third cell in each row combines the two shapes from that row using a symmetric difference operation: the first shape with the second shape cut out of it. Row 3 gives a square with a triangle-shaped cutout.

What comes next: 1, 4, 27, 256, ___?

Answer: 3125

Each number is n^n: 1¹=1, 2²=4, 3³=27, 4⁴=256, 5⁵=3125. The base and exponent are the same number, increasing by 1 each time.

A row of figures: [3×3 grid of dots, all black] → [3×3 grid, top row now white] → [3×3 grid, top two rows white, bottom row black] → [?]. What comes next?

Answer: 3×3 grid with all dots white

One row of dots turns white per step from top to bottom; after 3 steps all rows are white.

Which word best completes: 'The scientist's theory was so ______ that even experts struggled to understand it.'

Answer: ABSTRUSE

ABSTRUSE means difficult to understand — perfectly describes something that even experts struggle with.

In a letter-number-letter pattern: B2D means 'skip 2 letters after B to get D'. What does G3K represent?

Answer: Skip 3 letters after G to reach K

G, skip H-I-J (3 letters), land on K — the number indicates how many letters to skip.