50 free Riddles and Brain Teasers trivia questions with answers — trivia quiz, new questions added Aug 2026.
Riddle trivia in two flavours. About half of these 50 questions hand you a classic riddle and four possible answers: the Sphinx's creature with one voice, Samson's eater that gave something to eat, the featherless bird on the wall, the twelve-spoked wheel with 720 sons, and the man with seven wives on the road to St Ives. The other half are brain teasers and trivia about riddles themselves: why you should switch doors in the Monty Hall problem, where the missing dollar went, who really wrote 'Einstein's riddle', and what Gollum wagered against Bilbo. It is built for quiz nights, classrooms and long car journeys, and it works for anyone from a sharp ten-year-old to a logic-puzzle veteran. Every question has one right answer and a short explanation that gives away the trick, so you learn the riddle as well as the answer. Every answer is checked against a cited source before publishing, so the solutions here are the accepted ones rather than internet guesses.
30 of 50 questions with answers and explanations. Play the quiz
Q 01What was Oedipus's answer to the Sphinx's riddle of the four-, two- and three-footed creature?
Man
A person crawls as a baby, walks upright as an adult and leans on a stick in old age.
Q 02In some accounts the Sphinx asked a second riddle: which two sisters each give birth to the other?
Day and night
The pair endlessly produce each other, which is the whole trick.
Q 03What did Samson's riddle 'Out of the eater came something to eat, and out of the strong came something sweet' describe?
Honey in a lion's carcass
The guests only got the answer by extorting it from Samson's wife, and he paid the lost bet with thirty stolen suits.
Q 04The nursery rhyme 'Humpty Dumpty' probably began life as a riddle. What was the answer?
An egg
The trick relied on 'humpty dumpty' also being 18th-century slang for a short, clumsy person, who might survive a fall where an egg would not.
Q 05In 'As I was going to St Ives', what is the usual trick answer to how many were going to St Ives?
Just one
Only the narrator is actually said to be heading there; the man and his entourage are simply met on the road.
Q 06If everyone in the St Ives rhyme, kits and all, were going to St Ives, how many would that be including the narrator?
2,802
That is the narrator, the man, 7 wives, 49 sacks, 343 cats and 2,401 kits.
Q 07The Mad Hatter asks Alice 'Why is a raven like a writing desk?' What answer does the Hatter himself give?
He hasn't the slightest idea
Lewis Carroll later invented an answer for readers who kept asking, and puzzle-maker Sam Loyd offered the Poe one.
Q 08In Turandot, the princess asks what is born each night and dies each dawn. What does Calaf answer?
Hope
His second answer is 'blood', for the thing that flickers red and warm like a flame but is not fire.
Q 09What answers Turandot's second riddle: 'flickers red and warm like a flame, but is not fire'?
Blood
A wrong answer to any of the three riddles means execution for the suitor.
Q 10What is the 'featherless bird' that lands on a wall until the wind blows it off in the Central European riddle?
A snowflake
The 'wind' is really the sun's warmth in some versions, melting the flake away.
Q 11The worldwide 'writing riddle' runs 'White field, black seeds'. What are the field and seeds?
A page and its letters
The eighth-century Veronese Riddle adds oxen for the scribe's fingers and a plough for the pen.
Q 12What does a Rig Veda riddle mean by a 'twelve-spoked wheel, upon which stand 720 sons of one birth'?
The year
Twelve months, and 360 days plus 360 nights make the 720 'sons'.
Q 13What animal does the medieval riddle 'Four hang, two point the way, two ward off dogs, one dangles behind' describe?
A cow
Four teats, two horns, two back legs and a tail; a 13th-century Icelandic version survives.
Q 21Which logician named the Knights and Knaves puzzles, where knights tell the truth and knaves lie, in 1978?
Raymond Smullyan
The name comes from his book What Is the Name of This Book?
Q 22On Smullyan's island, why can no inhabitant ever say 'I am a knave'?
Whether honest or dishonest, the speaker would contradict their own nature
That single observation cracks most puzzles of the type.
Q 23In George Boolos's 1996 'Hardest Logic Puzzle Ever', the gods True, False and Random answer only in which words?
Da and ja
Q 14In the German riddle where Two-legs sits on Three-legs holding One-leg, what is Three-legs?
A stool
Two-legs is a person, Four-legs a dog and One-leg the ham hock they are fighting over.
Q 15In Rumpelstiltskin, what must the queen do within three days to keep her child?
Guess the imp's name
She only succeeds because a messenger overhears him singing his own name.
Q 16In the Monty Hall problem, what are your odds of winning the car if you switch doors?
2/3
Marilyn vos Savant's 1990 Parade column saying 'switch' drew thousands of angry letters, many from people with PhDs.
Q 17In the missing dollar riddle ($30 paid, $3 back, bellhop keeps $2), where does the 'missing' dollar go?
Nowhere: the $27 already includes the $2 tip
Adding the tip to the $27 double-counts it; $25 in the till plus $2 tip is the $27 the guests paid.
Q 18In the classic wolf, cabbage and third-passenger river puzzle, which passenger crosses first?
The goat
The oldest known version is in a 9th-century manuscript by Alcuin of York.
Q 19What is the minimum number of moves needed to solve a Tower of Hanoi puzzle with three disks?
7
The general formula is 2 to the power n, minus 1; 64 disks would take 585 billion years at one move a second.
Q 20Who invented the Tower of Hanoi puzzle in 1883, hiding his name in the anagram 'N. Claus de Siam'?
Édouard Lucas
The booklet's legend of Brahmins moving 64 golden disks was pure marketing.
You do not know which word means yes, which is what makes it hard.
Q 24The Zebra Puzzle is often called whose 'riddle', despite no evidence he wrote it?
Albert Einstein
Its 1962 Life International version mentions cigarette brands that did not exist in his boyhood.
Q 25In the bridge and torch puzzle with crossing times 1, 2, 5 and 8 minutes, what is the fastest total in minutes?
15
The trick is sending the two slowest across together so their times do not both count separately.
Q 26The nine dots puzzle asks you to join a 3×3 grid with how many straight lines without lifting the pen?
Four
The solution requires drawing beyond the grid, the origin of the phrase 'thinking outside the box'.
Q 27The 2015 viral logic puzzle 'Cheryl's Birthday' came from a maths olympiad in which country?
Singapore
The answer is July 16; a TV presenter mistook it for a primary-school exam question and it spread worldwide.
Q 28Which paradox says an expected-value calculation suggests you should always swap, though the choices are symmetric?
The two envelopes problem
One envelope holds twice as much as the other; the flawed argument says switching gains double while only risking half.
Q 29Which psychologist coined the term 'lateral thinking' in 1967?
Edward de Bono
He used the Judgement of Solomon and the nine dots puzzle as his early examples.
Q 30A riddle whose answer is a joke punchline, like 'Why did the chicken cross the road?', is called what?
A conundrum
A conundrum does not expect you to know the answer; it is a set-up for the gag.