Ten riddles that make you think, each answer under a cover: work it out, then tap Show answer.
Brain Teaser Riddles
Matchsticks spell a false sum in Roman numerals: XI + I = X. Move one matchstick to make it true.
A will leaves 17 camels to three children: one half to the first, one third to the second and one ninth to the third. No camel may be cut up. A neighbor rides over on her own camel and solves it. How?
Why would a barber rather cut the hair of two strangers than of one regular customer?
My first falls in winter. My second is a person. Together I stand in the yard until the sun comes out. What am I?
A man who always lies says: "All of my hats are green." What can you be sure of?
All zibs are wumps, and all wumps are tocks. Are all zibs tocks?
A lamp is off. You press its switch seven times. Is it on or off?
You are third in a line. The person at the front leaves, and then the next one leaves too. Where are you now?
The word CHICKEN carries a shorter word for a female chicken, with its letters in the right order. Which word?
My first is in cup but not in cut. My second is in bolt but not in boat. My third is in bead but not in bed. My fourth is in tent but not in test. My fifth is in pet but not in pat. My sixth is in cart but not in car. My whole circles a star. What am I?
These brain riddles, or mind riddles, come in five kinds, and each has one answer you can check: logic, number puzzles with small numbers, lateral thinking, wordplay, and picture puzzles told in words.
Read the full guide
Brainteaser riddles of five kinds
The menu under the button keeps one kind. Logic and Number puzzles can be worked out on paper. Lateral thinking hides a wrong assumption. Wordplay turns on letters. Picture puzzles told in words are puzzle riddles to try with coins or matchsticks on the table.
The answer, and why
Tap Show answer under a teaser. The answer comes first, then one line that says why it is right. Choose More filters in the menu for Level: Easy, Medium or Hard, by the editors' judgment.
Tips
Say what you are assuming out loud. In the lateral set, the answer is usually hiding behind it.
Print gives the teasers with a line under each and the answers on a page of their own.
Questions and answers
What are mind benders riddles?
Another name for brain teasers: short puzzles that bend your first idea of the answer. Try one. A lamp is off, and you press its switch seven times: is it on or off? On, because seven is odd.
Are these brain games and riddles for a group?
Yes. Read one aloud, let the table argue, and open the cover when somebody commits to an answer. Keep score on paper if you like. The tool has no teams and no timer.
Are riddles good for your brain?
This page makes no health or memory claim. What a teaser does give is a few minutes of working on one problem, often with other people, and a checkable answer at the end.
How do you create a riddle or brainteaser?
Start from the answer. List what is true of it, then describe it using the truths that point somewhere else first. Test it on one person: if they groan after the answer and not before, it works.
A card carries three sentences. One: exactly one sentence on this card is false. Two: exactly two sentences on this card are false. Three: all three sentences on this card are false. Which sentence is true?Answer: The second. If one were true, the other two would be false, which makes two false, not one. If three were true, it would itself be false. With two true, sentences one and three are the two false ones, and everything fits.
A clock takes 5 seconds to strike six o'clock. How long does it take to strike twelve o'clock?Answer: 11 seconds. Six strokes have five gaps between them, so a gap is one second. Twelve strokes have eleven gaps.
A club meets every third day. The first meeting is on a Monday. On which day of the week is the fourth meeting?Answer: Wednesday. Monday, Thursday, Sunday, Wednesday: three meetings later is nine days later, a week and two days.
A drawer holds 10 red socks and 10 blue socks. In the dark, how many must you take to be certain of holding two red ones?Answer: 12. The first ten could all be blue. The next two have to be red.
A hallway has 100 closed lockers. The first student opens every locker. The second changes every 2nd locker, the third every 3rd, and so on up to the 100th student. How many lockers are open at the end?Answer: 10. A locker is changed once for each number that divides it. Only square numbers have an odd count of divisors, and there are ten squares up to 100: 1, 4, 9 and so on to 100.
A lamp is off. You press its switch seven times. Is it on or off?Answer: On. Each press changes it. An odd number of presses leaves it changed from where it began.
A man who always lies says: "All of my hats are green." What can you be sure of?Answer: He has at least one hat that is not green. His sentence is false. For "all of my hats are green" to be false, he must own a hat, and at least one of his hats must be another color.
All zibs are wumps, and all wumps are tocks. Are all zibs tocks?Answer: Yes. Every zib is a wump, and every wump is a tock, so every zib is a tock.
Four cards lie on a table, showing E, T, 6 and 3. Each has a letter on one side and a number on the other. Someone claims: "If a card has a vowel on one side, it has an even number on the other." Which cards must you turn over to test the claim?Answer: The E and the 3. The E could hide an odd number, and the 3 could hide a vowel: either would break the rule. The T and the 6 cannot break it whatever is on their backs.
How many people must be in a room before you can be certain that two of them were born in the same month?Answer: 13. Twelve people could each have a different month. The thirteenth must share one.
I am thinking of a whole number from 1 to 8. You may ask questions that I answer yes or no. What is the fewest questions that will always find my number?Answer: Three. Each question can cut the choices in half: 8, then 4, then 2, then 1.
On an island, some people always tell the truth and the rest always lie. You ask every islander: "Are you a liar?" What does every single one of them answer?Answer: No. A truth-teller truthfully says no. A liar, who would have to say yes to be honest, lies and says no.
Pat is looking at Quinn, and Quinn is looking at Rob. Pat is married. Rob is not. Is a married person looking at an unmarried person?Answer: Yes. Nobody says whether Quinn is married, and it does not matter. If Quinn is, Quinn is looking at unmarried Rob. If Quinn is not, married Pat is looking at Quinn.
Sixteen players enter a knockout tournament: lose once and you are out. How many matches are played to find the champion?Answer: 15. Every match knocks out exactly one player, and fifteen players have to be knocked out.
Three friends pay 10 dollars each for a 30-dollar room. The clerk finds the room costs 25 and sends 5 back with a helper, who keeps 2 and gives each friend 1. Now each paid 9, which makes 27, and the helper has 2: 29. Where is the missing dollar?Answer: There is no missing dollar. The 27 dollars already include the helper's 2: 25 for the room and 2 for the helper. Adding the 2 again is the trick. The right sum is 27 paid plus 3 returned.
Three switches outside a closed room each work one of three old-fashioned bulbs inside. You may flip switches as you like, but you may open the door only once. How do you match every switch to its bulb?Answer: Turn one switch on for a few minutes, turn it off, turn a second one on, and go in. The bulb that is lit belongs to the second switch. Of the two dark bulbs, the warm one belongs to the first switch and the cold one to the third.
Two boxes, one prize. The sign on box A says: "The prize is in this box." The sign on box B says: "Exactly one of these two signs is true." Where is the prize?Answer: In box B. Suppose the prize were in A, so sign A is true. Then sign B can be neither true (that would make two true signs) nor false (that would leave exactly one true sign, as it says). So the prize is not in A.
Two doors: one leads out, one leads back in. Two guards: one always lies, one always tells the truth, and you do not know which is which. You may ask one guard one question. What do you ask?Answer: Ask either guard which door the other guard would call the way out, then take the other door. The liar lies about the honest answer, and the honest guard truthfully reports the liar's lie. Either way you are pointed at the wrong door.
You are third in a line. The person at the front leaves, and then the next one leaves too. Where are you now?Answer: At the front. Two people left from ahead of you, so you moved up two places.
You have two ropes and a lighter. Each rope burns for exactly one hour, but not at a steady speed. How can you measure 45 minutes?Answer: Light the first rope at both ends and the second at one end; when the first is gone, light the other end of the second. A rope lit at both ends lasts 30 minutes. At that moment the second rope has 30 minutes left, and lighting its other end halves that to 15. 30 + 15 = 45.
Number puzzles 20
A chocolate bar is 4 squares wide and 6 squares long. You may break one piece along a straight line each time. How many breaks does it take to separate all 24 squares?Answer: 23. Every break turns one piece into two, so each break adds one piece. To go from 1 piece to 24 takes 23 breaks, however you do it.
A clock shows exactly six o'clock. What is the angle between its two hands?Answer: 180 degrees. The hands point straight up and straight down, which makes a straight line: half of a full turn.
A father is three times as old as his son. In twelve years he will be twice as old as his son. How old are they now?Answer: 36 and 12. In twelve years they are 48 and 24, and 48 is twice 24.
A pizza is cut with four straight cuts, and every cut goes through the center. How many slices are there?Answer: Eight. Each cut through the center makes two new edges, so four cuts make eight slices.
A staircase has 10 steps. You climb it taking either 1 step or 2 steps at a time. In how many different ways can you reach the top?Answer: 89. The ways to reach a step are the ways to reach the step below plus the ways to reach the one below that: 1, 2, 3, 5, 8, 13, 21, 34, 55, 89.
A will leaves 17 camels to three children: one half to the first, one third to the second and one ninth to the third. No camel may be cut up. A neighbor rides over on her own camel and solves it. How?Answer: She lends her camel to make 18, hands out 9, 6 and 2, and rides home on the one left over. 9 + 6 + 2 = 17. The three fractions add up to seventeen eighteenths, not to one, which is why one camel comes back.
Add up all twelve numbers on the face of a clock. What do you get?Answer: 78. 1 + 12, 2 + 11, 3 + 10 and so on make six pairs of 13.
Add up every whole number from 1 to 20 without a calculator. What is the quick way, and what is the total?Answer: 210. Pair 1 with 20, 2 with 19, and so on: ten pairs that each make 21.
At exactly a quarter past three, what is the angle between the two hands of a clock?Answer: 7.5 degrees. The minute hand points at the 3. The hour hand has moved a quarter of the way from the 3 to the 4, and that gap is 30 degrees: a quarter of 30 is 7.5.
Count aloud from 1 to 30. How many of the numbers you say have a 3 in them?Answer: Four. 3, 13, 23 and 30.
Half of a number is 2 more than a third of it. What is the number?Answer: 12. Half of 12 is 6 and a third of 12 is 4.
Multiply together all the whole numbers from 1 to 10. How many zeros are at the end of the answer?Answer: Two. The answer is 3,628,800. A zero at the end needs a 2 and a 5, and only 5 and 10 supply a 5.
The pages of a notebook are numbered from 1 up, and the numbers use 192 digits in all. How many pages does the notebook have?Answer: 100. Pages 1 to 9 use 9 digits and pages 10 to 99 use 180. That leaves 3 digits, which is one more page: page 100.
Two numbers add up to 15, and one is 3 more than the other. What are they?Answer: 9 and 6. Take away the extra 3 and split the 12 that is left: 6 and 6. Give the 3 back to one of them.
Two trains start 100 miles apart and roll toward each other at 50 miles an hour each. A fly leaves the front of one train at 75 miles an hour and flies back and forth between them until they meet. How far does the fly travel?Answer: 75 miles. The trains close 100 miles at 100 miles an hour together, so they meet after one hour. The fly flies for that hour.
Using quarters, dimes, nickels and pennies, what is the fewest coins that make exactly 99 cents?Answer: Nine. Three quarters, two dimes and four pennies: 75 + 20 + 4.
What is double one half of 7?Answer: 7. Halving and doubling undo each other.
What is one half of two thirds of three quarters of four fifths of five sixths of 600?Answer: 100. The fractions cancel in a chain, top against bottom, and leave one sixth. A sixth of 600 is 100.
Write down eight 8s. Put plus signs between some of them so that the total is exactly 1,000.Answer: 888 + 88 + 8 + 8 + 8. 888 + 88 is 976, and three more 8s add 24.
You drive to a town at 30 miles an hour and come back along the same road at 60 miles an hour. What is your average speed for the whole trip?Answer: 40 miles an hour. Take a town 60 miles away: 2 hours out and 1 hour back is 120 miles in 3 hours. It is not 45, because more time is spent at the slow speed.
Lateral thinking 20
A cat jumps out of a window of a 20-story building and walks away without a scratch. How?Answer: It jumped from a ground-floor window. A tall building has low windows too.
A coin sits inside a bottle that is closed with a cork. How do you get the coin out without pulling the cork out and without breaking the bottle?Answer: Push the cork in. With the cork inside the bottle, the coin shakes out of the neck.
A drive takes an hour and twenty minutes going and eighty minutes coming back, on the same road at the same speed. Why the difference?Answer: There is no difference. An hour and twenty minutes is eighty minutes.
A horse jumps over a tower and lands on a small man, who vanishes at once. Where did this happen?Answer: On a chessboard. The horse is a knight, the tower is a rook, and the small man is a pawn that the knight captures.
A magician sets a bottle in the middle of a room and says: "I will now crawl into it." She does exactly what she said. How?Answer: She crawls into the room. The word it can mean the room as well as the bottle.
A table-tennis ball drops into a narrow pipe set upright in a concrete floor. The pipe is too deep for fingers, and you have no tools. How do you get the ball out?Answer: Pour water into the pipe. The ball floats up as the pipe fills.
A truck gets wedged under a low bridge. It cannot go forward or back, and the bridge cannot be raised. What is the simple way to free it?Answer: Let some air out of the tires. Softer tires lower the truck by an inch or two.
A window cleaner is washing the windows of the 25th floor when he slips and falls. He has no safety harness, and he is not hurt. How?Answer: He was inside the building. He was washing the inside of the windows and fell to the floor of the room.
A woman is reading in her room at night. The lamp is switched off, the room goes black, and she reads on without a pause. How?Answer: She is reading braille. Braille is read with the fingertips, so light makes no difference.
An explorer walks one mile south, one mile east and one mile north, and is back where she started. A bear walks by. What color is the bear?Answer: White. The walk closes at the North Pole, where the bears are polar bears. It also closes near the South Pole, and no bears live on that continent.
At a hardware store, 1 costs a dollar, 12 costs two dollars and 144 costs three dollars. What is being sold?Answer: House numbers. Each digit is one dollar: 1 is one digit, 12 is two and 144 is three.
How can you start a campfire with only one stick?Answer: Make sure the stick is a match. A match is a stick too.
How long is the answer to this question?Answer: How long. Read without the question mark, the question gives its own answer: two words, seven letters.
It is raining at midnight. Can you count on sunshine exactly 72 hours later?Answer: No. Seventy-two hours is three full days, so it will be midnight again.
Two friends play chess all afternoon. They play five games, there are no draws, and each of them wins the same number of games. How?Answer: They were not playing each other. Each of them played five games against other people.
Two students who sat at opposite ends of the room hand in exactly the same answers to a 20-question test. Neither one cheated. How?Answer: Both got every answer right. Two perfect papers are bound to match.
Why are the covers of manholes round and not square?Answer: A round cover cannot fall through its own hole. A square cover turned on edge and tilted fits through the diagonal of a square hole. A circle is the same width every way.
Why would a barber rather cut the hair of two strangers than of one regular customer?Answer: Two haircuts pay twice as much. The riddle invites you to look for something deeper than the price.
You are sitting in a parked car and can get out through a gold door, a silver door or a bronze door. Which door do you open first?Answer: The car door. You have to get out of the car before any of the others.
You must mail a ring to a friend. Anything sent in an unlocked box is stolen. You each have padlocks and keys, but neither of you has a key to the other's lock. How does the ring arrive safely?Answer: Lock the box with your padlock; your friend adds a second padlock and mails it back; you remove yours and mail it again. The box is never unlocked in the mail, and no key ever travels.
Wordplay 20
A country is hiding across the words of this sentence: "Have you ever heard such a din?" Which country?Answer: Chad. The end of SUCH, then A, then the D of DIN: C-H-A-D.
A desert animal is hiding across two words of this sentence: "She came late." Which animal?Answer: A camel. CAME and the L of LATE spell C-A-M-E-L.
My first bites. My second sweeps. Together I clean my first. What am I?Answer: A toothbrush. Tooth and brush.
My first falls in winter. My second is a person. Together I stand in the yard until the sun comes out. What am I?Answer: A snowman. Snow and man.
My first hears. My second goes on a finger. Together I hang from my first. What am I?Answer: An earring. Ear and ring.
My first is for frying. My second comes with candles. Together I am breakfast with syrup. What am I?Answer: A pancake. Pan and cake.
My first is in bat but not in at. My second is in cot but not in cat. My third is in hop but not in hip. My fourth is in bike but not in bite. My whole is read. What am I?Answer: A book. B, O, O, K.
My first is in cup but not in cut. My second is in bolt but not in boat. My third is in bead but not in bed. My fourth is in tent but not in test. My fifth is in pet but not in pat. My sixth is in cart but not in car. My whole circles a star. What am I?Answer: A planet. P, L, A, N, E, T.
My first is in rice but not in ice. My second is in man but not in men. My third is in pin but not in pen. My fourth is in can but not in cat. My whole falls from the clouds. What am I?Answer: Rain. R, A, I, N.
My first is in ship but not in hip. My second is in tin but not in in. My third is in bat but not in bit. My fourth is in car but not in cat. My whole shines at night. What am I?Answer: A star. S, T, A, R.
My first shines all day. My second is a blossom. Together I am a tall yellow plant that turns its face to my first. What am I?Answer: A sunflower. Sun and flower.
Read me forward and I am a piece of something. Read me backward and I am a snare. What word am I?Answer: Part. PART backward is TRAP.
Take the letters B and G with a gap between them. How many of the five vowels A, E, I, O and U make a word when dropped into the gap?Answer: All five. Bag, beg, big, bog and bug.
What does this stand for? 26 L of the A.Answer: 26 letters of the alphabet. L is for letters and A for alphabet.
What does this stand for? 52 C in a D.Answer: 52 cards in a deck. C is for cards and D for deck: four suits of thirteen.
What does this stand for? 64 S on a C.Answer: 64 squares on a chessboard. S is for squares and C for chessboard: eight rows of eight.
Which five-letter number has six left when you take two letters away?Answer: Sixty. SIXTY without T and Y is SIX.
The word BLOSSOM carries a shorter word that means the same thing, with its letters in the right order. Which word?Answer: Bloom. B-L-O-ss-O-M.
The word CHICKEN carries a shorter word for a female chicken, with its letters in the right order. Which word?Answer: Hen. c-H-ick-E-N.
The word MASCULINE carries a shorter word that means much the same, with its letters in the right order. Which word?Answer: Male. M-A-scu-L-in-E.
Picture puzzles told in words 20
A checkerboard has 64 squares. Two squares at opposite corners are cut away. Can 31 dominoes, each covering two squares, cover the 62 that are left?Answer: No. Opposite corners are the same color, so 32 squares of one color and 30 of the other remain. Every domino covers one of each.
A gardener plants ten trees in five straight rows with four trees in each row. What shape does the garden make?Answer: A five-pointed star. A star drawn with five lines has ten places where lines meet or end: five points and five inner crossings. Each line passes through four of them.
A square sheet of paper has four corners. You snip one corner off with a single straight cut. How many corners does the sheet have now?Answer: Five. The cut removes one corner and leaves two new ones in its place.
A wooden cube is painted red all over, then sawn into 27 equal small cubes. How many of the small cubes have no paint on them at all?Answer: One. Only the cube at the very center touches no outside face. The eight corner cubes have paint on three faces.
Fold a square of paper in half, then in half again to make a smaller square. Snip off the corner where the two folds meet, and unfold. How many holes are in the sheet, and where?Answer: One, in the middle. The corner where both folds meet is the center of the sheet, so the snip opens a single hole there.
Give a strip of paper half a twist and tape its ends together. How many sides does the loop have?Answer: One. Run a finger along it and you cover the whole surface without crossing an edge. It is called a Mobius strip.
How can you cut a round cake into eight equal pieces with only three straight cuts?Answer: Two cuts across the top make four quarters; one flat cut through the middle of the side makes eight. The third cut is sideways, level with the table, and halves every quarter.
Join the middle points of the three sides of a triangle. How many triangles are in the picture now?Answer: Five. Four small ones and the large one around them.
Lay six coins on a table so that they make three straight rows with three coins in each row.Answer: Arrange them as a triangle. A coin sits at each corner and one in the middle of each side. Each side is a row of three, and each corner coin counts in two rows.
Matchsticks spell a false sum in Roman numerals: IV = III + III. Move one matchstick to make it true.Answer: Move the I of IV to the other side of the V: VI = III + III. Six is three plus three.
Matchsticks spell a false sum in Roman numerals: XI + I = X. Move one matchstick to make it true.Answer: Move the I of XI to the front: IX + I = X. Nine plus one is ten.
Nine dots stand in a square, three rows of three. Join all nine with four straight lines, without lifting the pencil. What is the trick?Answer: Let the lines run out past the edge of the square. Start at a corner, draw along one side and on beyond it, come back on a slant through two dots to a point outside again, then along the next side and finish on the diagonal.
Read this line once, at normal speed, and count how many times the letter F appears: FRESH FISH OF FIVE KINDS, FRIED BY THE CHEF OF A FAMOUS CAFE OF OLD.Answer: 10. Most people miss the F in each OF, because it sounds like a V.
Read this out loud, quickly: ONCE UPON A A TIME. What is wrong with it?Answer: The word A is there twice. The eye skips a repeated small word.
Six matchsticks stand in a row like six fence posts. Add five more matchsticks and make nine. How?Answer: Spell the word NINE. N takes three sticks, I one, N three and E four: eleven in all, the six you had and five more.
Ten coins form a triangle that points up: one coin, then two, three and four. Move only three coins to make the triangle point down.Answer: Move the three corner coins. Put the top coin under the bottom row, and move the two end coins of the bottom row up beside the row of two. The rows now read four, three, two, one.
Three ordinary dice are stacked in a tower. You can see the top face, which shows 4. The two faces pressed against each other at each join, and the face on the table, are hidden. What do those five hidden faces add up to?Answer: 17. The top and bottom of each die add up to 7, so the six top and bottom faces total 21. Take away the 4 you can see.
Twelve matchsticks make a square window with four panes, two by two. Take away two matchsticks to leave exactly two squares.Answer: Take two inside matchsticks that meet at the center and make a corner. The big outside square is still whole, and one small pane, the one that kept both of its inside edges, is still closed. The other three panes have run together.
Why is the word AMBULANCE often painted backward on the front of an ambulance?Answer: So drivers ahead can read it in their mirrors. A mirror flips the letters back the right way.
You have six matchsticks. Make four triangles, each with sides one matchstick long, and break nothing.Answer: Build a pyramid. Lay three as a triangle on the table and stand the other three up from its corners to meet at a point. The base and the three sloping sides are four triangles with six edges.
How this list was compiled
Written by the Game Night Generator editors on October 3, 2026: 100 brain teasers with one checkable answer each, in five sets of 20. Most of these forms have been passed around for generations and belong to nobody (the two guards, the burning ropes, the nine dots, the missing dollar, the seventeen camels); every one is retold in the editors' own words, with the editors' own numbers where a number can be changed, and none was copied from a puzzle book or a site. Whatever can be computed was computed on the day the list was written: every sum, count and logic case was run by a script, and the letter riddles were checked against the word list of Webster's New International Dictionary, Second Edition (1934, public domain). Five teasers rest on a fact, read on October 3, 2026 in the English Wikipedia articles Dice, Manhole cover, Ambulance, Möbius strip, Polar bear and Bear (en.wikipedia.org; text under the Creative Commons Attribution-ShareAlike license). The three levels are the editors' judgment. Nothing here is a test of intelligence, and the page makes no claim about health or memory. This site is not connected with Wikipedia. Licence: own work