Logical Reasoning and Puzzles Flashcards

A statement reads: 'All glurps are snarks. No snarks are bleebs.' Which must be true?

Answer: No glurps are bleebs

All glurps are snarks, and no snarks are bleebs, so by transitivity no glurps can be bleebs.

A farmer has 17 sheep. All but 9 die. How many sheep are left?

Answer: 9

'All but 9' means 9 survive, regardless of the total starting number.

Which number is the odd one out? 4, 9, 16, 25, 32, 36

Answer: 32

4, 9, 16, 25, and 36 are all perfect squares; 32 is not (it's 2⁵).

You have a 3-gallon jug and a 5-gallon jug. How do you measure exactly 4 gallons using only these two jugs?

Answer: Fill the 5-gallon, pour into 3-gallon, empty 3-gallon, pour remainder into 3-gallon, fill 5-gallon, top off 3-gallon

Fill 5→pour into 3 (leaves 2 in 5)→empty 3→pour 2 into 3→fill 5 again→top off 3 (adds 1): 4 gallons remain in the 5-gallon jug.

If the day before yesterday was Thursday, what day is tomorrow?

Answer: Sunday

Day before yesterday = Thursday → yesterday = Friday → today = Saturday → tomorrow = Sunday.

A cube is painted red on all faces and then cut into 27 equal smaller cubes. How many small cubes have exactly 2 red faces?

Answer: 12

Exactly 2-face cubes sit on edges (not corners): a 3×3×3 cube has 12 edges, each contributing 1 such cube, totaling 12.

A logic puzzle states: 'Exactly one of these is true: (A) This statement is false. (B) 2+2=5.' Which is true?

Answer: Statement B is true

Statement B (2+2=5) is false; Statement A is a paradox that can't be evaluated as simply true, so in the context of 'exactly one is true,' B being false means A must be the true one — but actually the puzzle resolves by recognizing B is straightforwardly false and A is the odd one, making A the designated true statement.