Mind teaser riddles

Mind teaser riddles DEFAULT

45 Fun Brain Teasers for Kids [With Answers]

What are brain teasers?

Before you explore our examples, you might be wondering what brain teasers actually are.

Cambridge Dictionary defines a brain teaser as “a problem for which it is hard to find the answer, especially one which people enjoy trying to solve as a game.”

Brain teasers are a type of puzzle — and as the list below reveals, they come in many different forms. Often presented as a riddle, question or activity, brain teasers require a little extra brainpower to solve.

It's important to note that if you have any English language learners in your class, brain teasers for kids might pose a challenge for them. If that's the case, they might need you to walk them through the brain teaser more closely, or you can find ones that better suit their language level.

Brain teasers for kids differ from other complex or abstract problems because they’re usually done for fun. Although you can use them to analyze problem-solving and critical thinking skills, they’re often used as an amusing activity to encourage logical and lateral thinking, or thinking “outside the box.”

45 Brain teasers for kids

We’ve compiled a list of language, math and visual brain teasers to get your students thinking. Get inspired by the examples below — including answers!

Language brain teasers for kids

1. Riddles

When you hear the term “brain teaser,” a riddle is likely the first thing that comes to mind. Riddles are perplexing — sometimes misleading — questions or statements that require creative thought to solve.

Riddles are usually fun, and plenty of them can add some humour to your classroom.

Enjoy our list of riddles for kids below!

Riddles

a) Billy’s mother had five children. The first was named Lala, the second was named Lele, the third was named Lili, the fourth was named Lolo. What was the fifth child named?

b) Choose the correct sentence: “The yolk of the egg is white” or “the yolk of the egg is white.”

c) It’s as light as a feather, but the strongest person can’t hold it for more than five minutes. What is it?

d) The more there is, the less you see. What is it?

e) What gets more wet while it dries?

f) You can find it in Mercury, Earth, Mars, Jupiter and Saturn, but not in Venus or Neptune. What is it?

g) It likes food, but water kills it. What is it?

h) What’s full of holes but can still hold water?

i) Which is heavier, a pound of feathers or a pound of rocks?

j) How far can a dog run into the woods?

k) You’re driving a city bus. At the first stop, three women get on. At the second stop, one woman gets off and a man gets on. At the third stop, two children get on. The bus is blue and it’s raining outside in December. What colour is the bus driver’s hair?

l) There are three houses. One is red, one is blue and one is white. If the red house is to the left of the house in the middle, and the blue house is to the right of the house in the middle, where’s the white house?

m) It’s at the center of gravity and you can find it in Venus, but not Mars. What is it?

n) What goes on four feet in the morning, two in the afternoon and three in the evening?  (This is from the classic myth, Oedipus and the Riddle of the Sphinx)

o) What travels faster: heat or cold?

p) A man was walking in the rain in the middle of nowhere without a coat or an umbrella. He got soaked, but not a single hair on his head was wet. How can this be?

q) A cowboy rode into town on Friday. He stayed in town for three days and rode back out on Friday. How is this possible?

Answers

a) Billy

b) Neither. Egg yolks are yellow, not white!

c) Breath

d) Fog

e) A towel

f) The letter “R”

g) Fire

h) A sponge

i) Neither. Both weigh a pound!

j) Halfway. Once it reaches halfway, it’s running out of the woods.

k) Whatever colour your hair is. Remember, you’re driving the bus!

l) In Washington, D.C.

m) The letter “V”

n) A human. The times of day represent stages of human life. At the beginning of life, a baby crawls on four “feet.” As a person gets older, they walk on two feet. Later in life, a person will walk on three “feet” (two feet, plus a cane to help them walk).

o) Heat travels faster because you can catch a cold!

p) He was bald.

q) The horse’s name was Friday.

As a bonus, use these riddles to challenge preconceived notions and get students thinking about natural bias.

a) Two boxers are in a match scheduled for 12 rounds. (Pure boxing only - no kicking, UFC takedowns, or anything else). One of the boxers gets knocked out after only six rounds, yet no man throws a punch. How is this possible?

b) A father and son have a car accident and both are very injured. They are taken to separate hospitals for treatment. When the boy is taken in for an operation, the surgeon says, “I can’t do this surgery…. this boy is my son!” How is this possible?

Answers:

a) The two boxers are women.

b) The surgeon is the boy’s mother.

2. Language associations

These brain teasers for kids explore the complexities of the English language. Use them to boost student knowledge of sounds, words, spelling, categorization and more.a) Word association: find a word that associates with the following sets of words.

  1. Cake, swiss, cottage
  2. Glasses, screen, day
  3. Cream, cube, cap
  4. Knife, fly, cup

b) Find the mystery word. Replace the third letter of each word with a new letter to create a different word. When read vertically, the new letters will reveal the mystery word.

For example, the word MAKE could become MARE, MALE, MATE and so on. It’s your job to figure out which one works to create the mystery word. 

SAME

POKE

BOAT

NEAT

STOP   

BAKE

Hint: It’s something you’ll find outside.

c) Find rhyming pairs. Unscramble the words below so that each pair of words rhymes.

  1. RBAE & HREAS
  2. WNROED & UTRHNDE
  3. TUGHAT & HBTUGO
  4. ODULC & ODOG

Answers:

a)

  1. Cheese
  2. Sun
  3. Ice
  4. Butter

b)

SAFE

POLE

BOOT

NEWT

STEP

BARE

Mystery word: FLOWER

c)

  1. BEAR (or BARE) & SHARE
  2. WONDER & THUNDER
  3. TAUGHT & BOUGHT
  4. COULD & GOOD

You can also use printable brain teasers for kids like this one:

3. Lateral thinking problems

Lateral thinking problems require creative thinking with an indirect approach.

These questions require logic and careful thought to solve. The most notable example of a lateral thinking problem is the classic Monty Hall problem.

Here are two examples of lateral thinking problems kids can try to solve.

a) The river crossing problem

Image source: Popular Mechanics

A farmer is travelling with a fox, a goose, and a bag of beans. During his journey, he comes across a river with a boat to cross it.

The farmer can only fit one thing in the boat with him at a time. If left alone together, the fox will eat the goose or the goose will eat the beans. How does the farmer get everything across the river safely?

b) The light bulb problem

There are three light switches outside of a room-- labeled number one, number two, and number three. The door to the room is closed and you can’t see in. All three switches are off.

You need to figure out which switch belongs to which bulb. You can use the switches however you want to, but can only enter the room once. How do you do it?

Answers:

a) Here’s the step-by-step solution:

  1. The farmer brings the goose across the river first (if he leaves the goose alone, it will either eat the beans or be eaten by the fox).
  2. The farmer brings either the fox or the beans across and leaves the other one alone.
  3. Now the farmer has two items on the other side of the river, including the goose. If he leaves the goose again, the same problem will occur. So, the farmer must bring the goose back to the other side.
  4. The farmer brings the other item back (either the fox or the beans) and leaves the goose alone again. The fox and the beans are now on the other side of the river.
  5. The farmer returns and brings the goose across the river again.

b) Turn on the first switch and leave it on. Turn on the second switch for a few minutes, and then turn it off again. When you enter the room, one light bulb will be on. You’ll know it goes with switch one because you turned it on. Another bulb will be hot. You’ll know that goes with switch two because it was on for a little while. The bulb that’s off and cold goes with switch three because you didn’t touch it.

Math brain teasers for kids

Like math puzzles, these brain teasers for kids can increase engagement with math content and inspire your students to work on math concepts and problems outside of regular lessons.

1. Math riddles

These riddles are just as amusing as the ones above, but they’re math-focused. Use them to give students some extra math practice and encourage resourceful thinking.

Math riddles

a) Divide 30 by ½ and add 10. What’s the answer?

b) A clerk at the butcher shop is six feet tall and wears size 10 shoes. What does he weigh?

c) A farmer has 19 sheep on his land. One day, a big storm hits and all but seven run away. How many sheep does the farmer have left?

d) Your sock drawer only contains 18 white socks and 18 blue socks. How many times do you need to reach inside the drawer and take out a sock to guarantee a matching pair?

e) You planted sunflower seeds in your back garden. Every day, the number of flowers doubles. If it takes 52 days for the flowers to fill the garden, how many days would it take for them to fill half the garden?

f) Using only addition, how can you use eight eights to get the number 1,000?

g) When Ashley was 15, her mother was 37. Now, her mother is twice her age. How old is Ashley?

Answers

a) It's 70. You’re dividing 30 by ½, not by two. Thirty divided by ½ is the same thing as multiplying it by two, which is 60. Plus 10 makes 70!

b) Meat. He works at the butcher shop, so he weighs meat for a living.

c) Seven. The riddle says all but seven run away, meaning there are seven left who didn’t.

d) Three times. On the third time, you’ll get either a white or a blue sock to match with one of the other two you’ve already grabbed.

e) It would take 51 days. If the number of flowers doubles every day, half the garden would be full the day before, on the 51st day.

f) 888 +88 +8 +8 +8

g) Ashley is 22. Her mother is 22 years older, so when Ashley is 22, she’s now half her mother’s age.

2. Pattern problems

These questions require students to identify a pattern before they can answer a particular question. Kids must use creative and logical thinking to find the answers.

a) If:

2 + 2 = 44

3 + 3 = 96

4 + 4 = 168

5 + 5 = 2510

Then:

6 + 6 = ?

b) What makes this number unique: 8,549,176,320?

c) Solve the pattern puzzle below. Find the missing number to replace the question mark.

Image source: AOL

Answers:

a) The missing number is 3612. The answer is the number multiplied by itself and then the number added to itself. Six multiplied by six is 36, and six plus six is 12.

b) It contains each one-digit number, zero through nine, listed in alphabetical order.

c) The missing number is 17. Each number in the circle is the sum of the numbers in the opposite quadrant. In this case, the numbers are eight and nine — added together makes 17.

d) The answer is 14 (or 16), if you’re on the other side of the debate.

3. Prodigy Math Game

This math activity is a bit different from others on the list. It’s not a traditional brain teaser, but it can also be used as a fun, skill-building alternative to traditional math class.

Prodigy is a game-based learning platform that takes your students on an online fantasy adventure while they answer standards-aligned math questions. It’s engaging and effective at teaching necessary skills. 

Prodigy's free teacher tools help you differentiate learning, send assessments in-game and even collect student insights!

Create my free teacher account

Visual brain teasers for kids

1. Spot the difference

This ever-popular activity might remind you of your own childhood — and kids still love it! Spot the difference puzzles require lots of deduction and attention to detail.

Here’s an example of a printable spot the difference activity.

2. Rebus puzzles

A rebus is a visual word puzzle that uses lateral thinking to find its intended meaning. The word or phrase is depicted with a visual illustration, including letters and words. Students must think creatively to figure out the meaning from the clues they’re given. 

a)

Image source: Stack Exchange

Answers:

a) Top secret

b) Think outside the box

Visit the link below if you want more fun rebus puzzles for your students:

3. Optical illusions

Get tricky with your students! Optical illusions use visual tricks that alter the perception of what you’re really seeing. Students will love trying to figure out what’s really going on in these examples.

a) How many legs does the elephant have?

Image source: Brain Den

Answers:

a) Four

b) They’re exactly the same colour. If you place your finger over the spot where the squares meet, you can see they’re the same. Try this impossible paper puzzle if you want a more hands-on optical illusion. You can make one to show your class, then have students make their own as a fun brain teaser to show friends and family.

4. Stroop effect test

The Stroop effect was discovered in the 1930s by John Ridley Stroop. During the test, you’re given a list of colour names, with each word being a different colour than what they describe.

The test involves saying the colour of a word, rather than reading the word itself. Your mind must process the two conflicting pieces of information, which slows down reaction speed and requires careful thought to get through.

Image source: The Crafty Classroom

Benefits of brain teasers for kids

You know your students enjoy them, but did you know there are plenty of additional reasons to make brain teasers a regular activity in the classroom?

A study on the attention spans of six-year-olds found children who were given brain teasers were more attentive than those who were not — showing brain teasers were effective at boosting children’s attention spans.   

Brain teasers for kids can also:

  • Strengthen problem solving and critical thinking skills
  • Encourage lateral thinking and build new perspectives
  • Improve cognitive abilities like memory and processing speed
  • Inspire teamwork and communication
  • Engage students and motivate them to learn
  • Provide necessary breaks from traditional class work

How to use brain teasers in the classroom

In addition to their many learning advantages, brain teasers are a great way to break up the day and engage your students. Here are just a few ways you can use brain teasers for kids as a teaching strategy and maximize the benefits in your classroom:

  • Engagement-boosting activity before or after lessons
  • Bonus questions in assignments and tests
  • Optional “free time” activity
  • Encourage team building — split students into groups to solve them together
  • Supplement lessons — choose brain teasers about the subject you’re teaching

Final thoughts on brain teasers for kids

No matter what subject or skill you want to focus on, a brain teaser is a great addition to traditional teaching methods. Plus, it’s something students will actually be excited to do.

Remember that brain teaser are designed to be fun for kids. it’s not about finding the right answer, but the mental exercise they get from trying to find the solution.

Use any of the brain teasers in this list whenever you need a boost of energy in your classroom. Bonus points if you can stump any adults!

Create or log in to your free teacher account on Prodigy – a game-based learning platform for math that’s easy to use for educators and students alike. Aligned with standards across the English-speaking world, it’s loved by more than a million teachers and 50 million students.

Sign up now!
Sours: https://www.prodigygame.com/main-en/blog/brain-teasers-for-kids/

23 surprisingly simple riddles and brainteasers that most people get wrong

reading
PIC SNIPE/Shutterstock
  • Insider rounded up difficult riddles and brainteasers that most people can't answer. 
  • The answers are so obvious and simple that they often get overlooked. 
  • What comes once in a minute, twice in a moment, but never in a thousand years? The letter "M."
  • Visit Insider's homepage for more stories.

Sometimes puzzles are so obvious that they're nearly impossible to solve. 

Insider rounded up 23 riddles and brainteasers with simple answers that anyone could get wrong.

Read on to see if you can figure them out.

What comes once in a minute, twice in a moment, but never in a thousand years?

big ben clock face
antb/Shutterstock

Answer: The letter "M"

Source: Quora

What always ends everything?

everything
Insider

Answer: The letter "G"

Source: UpVee

I have seas without water, coasts without sand, towns without people, and mountains without land. What am I?

Aerial view of Santa Maria beach in Sal Island Cape Verde - Cabo Verde - Image
Shutterstock

Answer: A map

Source: Riddles.com

A man shaves several times a day but still has a beard. Who is he?

Shaving
Veles Studio/Shutterstock

Answer: A barber

Source: Grin

What coat is best put on wet?

painting house wall
Getty Images

Answer: A coat of paint

Source: Answers King

A clerk in a butcher shop stands 5'10" and wears size 13 shoes. What does he weigh?

pork ribs butcher
Frank Bean/Getty Images

Answer: Meat

Source: Quora

How much dirt is in a hole that measures 2 feet by 3 feet by 4 feet?

house home  dirt
Scott Olson/Getty Images

Answer: None

Source: RBT

Which is correct to say: "The yolk of the egg is white" or "The yolk of the egg are white?"

fried egg
Shutterstock

Answer: Neither, egg yolks are yellow

Source: Riddles.com

This belongs to you, but everyone else uses it more.

question
Sergey Nivens/Shutterstock
Sours: https://www.insider.com/brainteasers-with-simple-answers-2019-1
  1. Altium designer 18
  2. White mountain knives
  3. Maroon wrap car
  4. Golf painting ideas

Riddles are a form of brain teaser that comes in the form of a short story, statement, or question. They’re equal parts entertaining and bewildering and if you’re not careful, they’ll leave you with a headache.

So, what makes brain teaser riddles so engaging?  

We challenge ourselves with these brain teasers because they ask us to think in unique and innovative ways. We think we know the answer. But then we realize the answer can only be found by exercising our minds in an entirely new way.

9 Classic Adult Riddles To Test Your Intuitive Problem-Solving


When is the last time you encountered a riddle that left you feeling totally stumped? These brain teaser riddles will challenge you to think outside the box. Let’s see how many you can guess correctly!

    1. With the rich, I am blue, with the poor, I am red, with the bear I am warm, and with the frog, I am cool. What am I?
    2. What has two ends and no beginning?
    3. A construction worker fell from a 100-foot ladder, yet suffered not a scratch. How is this possible?
  1. I have a bed but never sleep. I have a mouth but never eat. What am I?
  2. Robert’s father has three sons: Curly, Larry, and ________?
  3. You just bought a one-storey 100-year-old house with its original oak floors still intact. The inspector comes to look at the house and is astonished because the stairs are made of _________?
  4. It belongs to you but is used by everyone except for you. What is it?
  5. I may be light as a feather but almost no one can hold me for very long. What am I?

9. If a rooster laid a brown egg, a yellow egg, and a white egg, what sort of chicks would hatch from each?

riddles for kids with answers

5 Riddles For Kids With Answers


These 5 brain teaser riddles for kids are suitable for all ages! How many can you get correct?

  1. I must be broken open before you can enjoy me. What am I? 
  2. I have an eye but cannot see. What am I? 
  3. I may be full of keys but I’m unable to open a single door. What am I? 
  4. I can be as small as an ant, as large as an elephant, I don’t weigh a thing, and you can never lose me. What am I? 
  5. No one can throw me, but everyone catches me once in awhile. What am I? 

9 Classic adult riddles (The answers)

Ready to check your mental prowess? Here are the answers to the brain teaser riddles above:

  1. Blood.
  2. A rope.
  3. He fell from the bottom rung.
  4. A river.
  5. Robert.
  6. What stairs? It’s a one-storey house.
  7. Your name.
  8. Your breath.
  9. Roosters don’t lay eggs.

5 Riddles for kids (The answers)

Did you enjoy solving the 5 riddles for kids? How many could you guess? Evaluate your progress by checking the answers:

  1. An egg.
  2. A needle.
  3. A piano.
  4. A shadow.
  5. A cold.
Sours: https://blog.mindvalley.com/brain-teaser-riddles/
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Who says mind-bending logic puzzles are just for kids? We've come up with 20 brand-new riddles for adults to test your critical thinking, mathematics, and logic skills. With difficulties ranging from easy, to moderate, to hard, there's something here for everyone.

So go grab a pencil and a piece of scratch paper and prepare to rip your hair out (and we really do mean that in the best way possible). When you think you've got the right answer, click the link at the bottom of each riddle to find the solution. Got it wrong? No worries, you have 19 other riddles to test out.

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Riddle #1: The King’s Orders Make for One Hell of a Brain Teaser

(Difficulty: Easy)

King Nupe of the kingdom Catan dotes on his two daughters so much that he decides the kingdom would be better off with more girls than boys, and he makes the following decree: All child-bearing couples must continue to bear children until they have a daughter!

But to avoid overpopulation, he makes an additional decree: All child-bearing couples will stop having children once they have a daughter! His subjects immediately begin following his orders.

After many years, what’s the expected ratio of girls to boys in Catan?

Hint

The likelihood of each baby born being a girl is, of course, 50 percent.

Solution

Ready for the solution? Click here to see if you’re right.


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Riddle #2: How Many Eggs Does This Hen Lay?

(Difficulty: Easy)

This problem is in honor of my dad, Harold Feiveson. It’s due to him that I love math puzzles, and this is one of the first problems (of many) that he gave me when I was growing up.

A hen and a half lays an egg and a half in a day and a half. How many eggs does one hen lay in one day?

Solution

Ready for the solution? Click here to see if you’re right.


Riddle #3: The Gold Chain Math Problem Is Deceptively Simple

(Difficulty: Moderate)

You’re rummaging around your great grandmother’s attic when you find five short chains each made of four gold links. It occurs to you that if you combined them all into one big loop of 20 links, you’d have an incredible necklace. So you bring it into a jeweler, who tells you the cost of making the necklace will be $10 for each gold link that she has to break and then reseal.

How much will it cost?

Solution

Ready for the solution? Click here to see if you’re right.


Riddle #4: Try to Solve This Pickleball Puzzle

(Difficulty: 🚨HARD🚨)

Kenny, Abby, and Ned got together for a round-robin pickleball tournament, where, as usual, the winner stays on after each game to play the person who sat out that game. At the end of their pickleball afternoon, Abby is exhausted, having played the last seven straight games. Kenny, who is less winded, tallies up the games played:

Kenny played eight games

Abby played 12 games

Ned played 14 games

Who won the fourth game against whom?

Hint

How many total games were played?

Solution

Ready for the solution? Click here to see if you’re right.


Riddle #5: Our Circuit Breaker Riddle Is Pure Evil. Sorry.

(Difficulty: 🚨HARD🚨)

The circuit breaker box in your new house is in an inconvenient corner of your basement. To your chagrin, you discover none of the 100 circuit breakers is labeled, and you face the daunting prospect of matching each circuit breaker to its respective light. (Suppose each circuit breaker maps to only one light.)

To start with, you switch all 100 lights in the house to “on,” and then you head down to your basement to begin the onerous mapping process. On every trip to your basement, you can switch any number of circuit breakers on or off. You can then roam the hallways of your house to discover which lights are on and which are off.

What is the minimum number of trips you need to make to the basement to map every circuit breaker to every light?

Hint

The solution does not involve either switching on or off the light switches in your house or feeling how hot the lightbulbs are. You might want to try solving for the case of 10 unlabeled circuit breakers first.

Solution

Ready for the solution? Click here to see if you're right.


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Riddle #6: Two Trains. Two Grandmas. Can You Solve This Tricky Math Riddle?

(Difficulty: Moderate)

Jesse’s two grandmothers want to see him every weekend, but they live on opposite sides of town. As a compromise, he tells them that every Sunday, he’ll head to the subway station nearest to his apartment at a random time of the day and will hop on the next train that arrives.

If it happens to be the train traveling north, he’ll visit his Grandma Erica uptown, and if it happens to be the train traveling south, he’ll visit his Grandma Cara downtown. Both of his grandmothers are okay with this plan, since they know both the northbound and southbound trains run every 20 minutes.

But after a few months of doing this, Grandma Cara complains that she sees him only one out of five Sundays. Jesse promises he’s indeed heading to the station at a random time each day. How can this be?

Hint

The trains always arrive at their scheduled times.

Solution

Ready for the solution? Click here to see if you’re right.


Riddle #7: Here's a Really [email protected]*#ing Hard Math Problem About Ants

(Difficulty: 🚨HARD🚨)

Max and Rose are ant siblings. They love to race each other, but always tie, since they actually crawl at the exact same speed. So they decide to create a race where one of them (hopefully) will win.

For this race, each of them will start at the bottom corner of a cuboid, and then crawl as fast as they can to reach a crumb at the opposite corner. The measurements of their cuboids are as pictured:

[image id='550345dc-6be5-438a-8605-ff8d57483b0c' mediaId='ae98d516-4b3c-4641-b153-afc915e1c8f2' align='center' size='small' share='false' caption='' expand='' crop='original'][/image]

If they both take the shortest possible route to reach their crumb, who will reach their crumb first? (Don’t forget they’re ants, so of course they can climb anywhere on the edges or surface of the cuboid.)

Hint

Remember: Think outside the box.

Solution

Ready for the solution? Click here to see if you’re right.


Riddle #8: This Peppermint Patty Riddle Is Practically Impossible

(Difficulty: 🚨HARD🚨)

You’re facing your friend, Caryn, in a “candy-off,” which works as follows: There’s a pile of 100 caramels and one peppermint patty. You and Caryn will go back and forth taking at least one and no more than five caramels from the candy pile in each turn. The person who removes the last caramel will also get the peppermint patty. And you love peppermint patties.

Suppose Caryn lets you decide who goes first. Who should you choose in order to make sure you win the peppermint patty?

Hint

First, solve for a pile of 10 caramels.

Solution

Ready for the solution? Click here to see if you’re right.


Riddle #9: Can You Solve the Great American Rail-Trail Riddle?

(Difficulty: Moderate)

This problem was suggested by the physicist P. Jeffrey Ungar.

Finally, the Great American Rail-Trail across the whole country is complete! Go ahead, pat yourself on the back—you’ve just installed the longest handrail in the history of the world, with 4,000 miles from beginning to end. But just after the opening ceremony, your assistant reminds you that the metal you used for the handrail expands slightly in summer, so that its length will increase by one inch in total.

“Ha!” you say, “One inch in a 4,000 mile handrail? That’s nothing!” But … are you right?

Let’s suppose when the handrail expands, it buckles upward at its weakest point, which is in the center. How much higher will pedestrians in the middle of the country have to reach in summer to grab the handrail? That is, in the figure below, what is h? (For the purposes of this question, ignore the curvature of the Earth and assume the trail is a straight line.)

[image id='14a0258d-04bd-492b-abb1-1fda09a959a7' mediaId='c7175701-3445-422b-a1de-be320d90f788' align='center' size='medium' share='false' caption='' expand='' crop='original'][/image]

Hint

Pythagoras is a fascinating historical figure.

Solution

Ready for the solution? Click here to see if you’re right.


Riddle #10: This Riddle Is Like an Especially Cruel SAT Problem. Can You Find the Answer?

(Difficulty: Moderate)

Amanda lives with her teenage son, Matt, in the countryside—a car ride away from Matt’s school. Every afternoon, Amanda leaves the house at the same time, drives to the school at a constant speed, picks Matt up exactly when his chess club ends at 5 p.m., and then they immediately return home together at the same constant speed. But one day, Matt isn’t feeling well, so he leaves chess practice early and starts to head home on his portable scooter.

After Matt has been scooting for an hour, Amanda comes across him in her car (on her usual route to pick him up), and they return together, arriving home 40 minutes earlier than they usually do. How much chess practice did Matt miss?

Hint

Consider the case where Amanda meets Matt exactly as she’s leaving their house.

Solution

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Riddle #11: Can You Get These 3 Movie Stars Across the River?

(Difficulty: Moderate)

Three movie stars, Chloe, Lexa, and Jon, are filming a movie in the Amazon. They’re very famous and very high-maintenance, so their agents are always with them. One day, after filming a scene deep in the rainforest, the three actors and their agents decide to head back to home base by foot. Suddenly, they come to a large river.

On the riverbank, they find a small rowboat, but it’s only big enough to hold two of them at one time. The catch? None of the agents are comfortable leaving their movie star with any other agents if they’re not there as well. They don’t trust that the other agents won’t try to poach their star.

For example, Chloe’s agent is okay if Chloe and Lexa are alone in the boat or on one of the riverbanks, but definitely not okay if Lexa’s agent is also with them. So how can they all get across the river?

Hint

There isn’t just one way to solve this problem.

Solution

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Riddle #12: This Ludicrously Hard Riddle Is Our Tribute to a Late Math Genius. Can You Figure It Out?

(Difficulty: 🚨HARD🚨)

On April 11, John Horton Conway, a brilliant mathematician who had an intense and playful love of puzzles and games, died of complications from COVID-19. Conway is the inventor of one of my favorite legendary problems (not for the faint of heart) and, famously, the Game of Life. I created this problem in his honor.

Carol was creating a family tree, but had trouble tracking down her mother’s birthdate. The only clue she found was a letter written from her grandfather to her grandmother on the day her mother was born. Unfortunately, some of the characters were smudged out, represented here with a “___”. (The length of the line does not reflect the number of smudged characters.)

“Dear Virginia,

Little did I know when I headed to work this Monday morning, that by evening we would have a beautiful baby girl. And on our wedding anniversary, no less! It makes me think back to that incredible weekend day, J___ 27th, 19___, when we first shared our vow to create a family together, and, well, here we are! Happy eighth anniversary, my love.

Love, Edwin”

The question: When was Carol’s mother born?

Hint

This problem is inspired by Conway’s Doomsday Rule.

Solution

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Riddle #13: To Solve This Twisty Math Riddle, You Just Need One Belt and One Earth

(Difficulty: Moderate)

Imagine you have a very long belt. Well, extremely long, really … in fact, it’s just long enough that it can wrap snugly around the circumference of our entire planet. (For the sake of simplicity, let’s suppose Earth is perfectly round, with no mountains, oceans, or other barriers in the way of the belt.)

Naturally, you’re very proud of your belt. But then your brother, Peter, shows up—and to your disgruntlement, he produces a belt that’s just a bit longer than yours. He brags his belt is longer by exactly his height: 6 feet.

If Peter were also to wrap his belt around the circumference of Earth, how far above the surface could he suspend the belt if he pulled it tautly and uniformly?

Hint

Earth’s circumference is about 25,000 miles, or 130 million feet … but you don’t need to know that to solve this problem.

Solution

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Riddle #14: This Elbow Tapping Riddle Is Diabolical. Good Luck Solving It.

(Difficulty: 🚨HARD🚨)

In some future time, when the shelter-in-place bans are lifted, a married couple, Florian and Julia, head over to a bar to celebrate their newfound freedom.

They find four other couples there who had the same idea.

Eager for social contact, every person in the five couples enthusiastically taps elbows (the new handshake) with each person they haven’t yet met.

It actually turns out many of the people had known each other prior, so when Julia asks everyone how many elbows they each tapped, she remarkably gets nine different answers!

The question: How many elbows did Florian tap?

Hint

What nine answers did Julia hear?

Solution

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Riddle #15: You'll Need a Drink After Trying to Solve This Whisky Riddle

(Difficulty: Easy)

Alan and Claire live by the old Scottish saying, “Never have whisky without water, nor water without whisky!” So one day, when Alan has in front of him a glass of whisky, and Claire has in front of her a same-sized glass of water, Alan takes a spoonful of his whisky and puts it in Claire’s water.

Claire stirs her whisky-tinted water, and then puts a spoonful of this mixture back into Alan’s whisky to make sure they have exactly the same amount to drink.

So: Is there more water in Alan’s whisky, or more whisky in Claire’s water?And does it matter how well Claire stirred?

Hint

The size of the spoon does not matter.

Solution

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Riddle #16: The Doodle Problem Is a Lot Harder Than It Looks. Can You Solve It?

(Difficulty: Moderate)

This week’s riddle is relatively simple—but sinister all the same.

The question: Can you make 100 by interspersing any number of pluses and minuses within the string of digits 9 8 7 6 5 4 3 2 1? You can’t change the order of the digits! So what’s the least number of pluses and minuses needed to make 100?

[image id='15ce5610-c097-47c9-881a-4ec04561055c' mediaId='5e1d9f7e-9b74-4b87-932d-c18ebca1c1a7' align='center' size='medium' share='false' caption='' expand='' crop='2x1'][/image]

For instance, 98 - 7 - 6 + 54 - 32 shows one way of interspersing pluses and minuses, but since it equals 107, it’s not a solution.

I call this a “doodle problem”: one that’s best worked on during meetings where you might be doodling otherwise.

Hint

You might want to start looking for solutions that use a total of seven pluses and minuses (although there are ways to use fewer).

Solution

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Riddle #17: This Math Puzzle Stumped Every Scientist but One. Think You Can Crack It?

(Difficulty: HARD)

In honor of Freeman Dyson, the renowned physicist who died last month, here’s a legendary tale demonstrating his quick wit and incredible brain power.

One day, in a gathering of top scientists, one of them wondered out loud whether there exists an integer that you could exactly double by moving its last digit to its front. For instance, 265 would satisfy this if 526 were its exact double—which it isn’t.

After apparently just five seconds, Dyson responded, “Of course there is, but the smallest such number has 18 digits.”

This left some of the smartest scientists in the world puzzling over how he could have figured this out so quickly.

So given Dyson’s hint, what is the smallest such number?

Hint

My second grader has recently learned how to add a 3-digit number to itself using the classic vertical method:

[image id='35fe29ff-b8d4-456f-bfa1-fce6b7e44dd5' mediaId='43635338-6146-4797-ab02-e207f1aa5351' align='center' size='small' share='false' caption='' expand='' crop='original'][/image]

18-digit numbers, of course, can be added in the same way.

Solution

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Riddle #18: Figure Out What’s on Her Forehead

(Difficulty: Moderate)

Cecilia loves testing the logic of her very logical friends Jaya, Julian, and Levi, so she announces:

“I’ll write a positive number on each of your foreheads. None of the numbers are the same, and two of the numbers add up to the third.”

She scribbles the numbers on their heads, then turns to Jaya and asks her what her number is. Jaya sees Julian has 20 on his forehead, and Levi has 30 on his. She thinks for a moment and then says, “I don’t know what my number is.” Julian pipes in, “I also don’t know my number,” and then Levi exclaims, “Me neither!” Cecilia gleefully says, “I’ve finally stumped you guys!”

“Not so fast!” Jaya says. “Now I know my number!”

What is Jaya’s number?

Hint

Jaya could be one of two numbers, but only one of those numbers would lead to Julian and Levi both not knowing their numbers. Why?

Solution

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Riddle #19: Can You Get Keanu Reeves Elected As President?

(Difficulty: Moderate)

It’s 2024, and there are five candidates running in the democratic primary: Taylor Swift, Oprah Winfrey, Mark Cuban, Keanu Reeves, and Dwayne Johnson. (Hey, it could happen.) As usual, the first primary is in Iowa.

In an effort to overcome its embarrassment after the 2020 caucus debacle, the Iowa Democratic Party has just announced a new, foolproof way of finding the best candidate: there will be four consecutive elections.

First, candidate 1 will run against candidate 2. Next, the winner of that will run against candidate 3, then that winner will run against candidate 4, and finally the winner of that election will run against the final candidate. By the transitive property, the winner of this last election must be the best candidate ... so says the Iowa Democratic Party.

Candidate Keanu has been feeling pretty low, as he knows he is ranked near the bottom by most voters, and at the top by none. In fact, he knows the Iowa population is divided into five equal groups, and that their preferences are as follows:

[image id='f122bead-3ff6-4057-9c10-e43ee9f48377' mediaId='716dc0a3-47ef-4f6b-8e6a-7617e69b97e1' align='center' size='medium' share='false' caption='' expand='' crop='original'][/image]

Keanu is childhood friends with Bill S. Preston, Esq., the new head of the Iowa Democratic Party. Preston, confident that the order of the candidates doesn’t matter for the outcome, tells Keanu he can choose the voting order of the candidates.

So what order should Keanu choose?

Hint

How would Keanu fare in one-to-one races against each candidate?

Solution

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Riddle #20: Who Opened All These Damn Lockers?

(Difficulty: Moderate)

There are 100 lockers that line the main hallway of Chelm High School. Every night, the school principal makes sure all the lockers are closed so that there will be an orderly start to the next day. One day, 100 mischievous students decide that they will play a prank.

The students all meet before school starts and line up. The first student then walks down the hallway, and opens every locker. The next student follows by closing every other locker (starting at the second locker). Student 3 then goes to every third locker (starting with the third) and opens it if it’s closed, and closes it if it’s open. Student 4 follows by opening every fourth locker if it’s closed and closing it if it’s open. This goes on and on until Student 100 finally goes to the hundredth locker. When the principal arrives later in the morning, which lockers does she find open?

Hint

Make sure you pay attention to all of the factors.

Solution

Ready for the solution? Click here to see if you’re right.


🎥 Now Watch This:

[mediaosvideo align='center' embedId='b58fa136-cd5c-4321-bb84-cfbf804bfddd' mediaId='1e354887-635c-494b-b6ed-d9f4f7f266af' size='large'][/mediaosvideo]

Laura FeivesonLaura Feiveson is an economist for the government, a storyteller, and a lifelong enthusiast of math puzzles.  She lives in Washington, DC with her husband and two daughters. 

This content is created and maintained by a third party, and imported onto this page to help users provide their email addresses. You may be able to find more information about this and similar content at piano.io

Sours: https://www.popularmechanics.com/science/math/a31153757/riddles-brain-teasers-logic-puzzles/

Riddles mind teaser

14 brainteasers and riddles only smart people can solve

woman thinking
Shutterstock

Who doesn't love the feeling of satisfaction you get after you solve a brain teaser? While intellectual jokes can be understood in seconds, riddles take a bit longer to unpack, which makes the payoff even better.

INSIDER combed through Reddit to compile a list of challenging logic problems, word puzzles, and more.

You'll see the answers to most of these brain teasers in the caption below each picture. Scroll down slowly to avoid seeing the solution too soon. Don't worry — we've also included explanations in case you get stumped on any of these puzzles.

Here are 14 riddles that may take you some time to solve:

2. You're escaping a labyrinth, and there are three doors in front of you. The door on the left leads to a raging inferno. The door in the center leads to a deadly assassin. The door on the right leads to a lion that hasn't eaten in three months. Which door do you choose?

ross island india
Matyas Rehak/Shutterstock

Explanation: The lion would be dead after not eating for three months.

SourceAntmanIV, Reddit

3. If I am holding a bee, what do I have in my eye?

bees
Shutterstock

Explanation: This riddle is a play on the proverb, "Beauty is in the eye of the beholder." In this case, you are the "bee-holder." Thus, beauty is in your eye.

Source: lipwiggler, Reddit

4. An old man dies, leaving behind two sons. In his will, he orders his sons to race with their horses, and the one with the slower horse will receive his inheritance. The two sons race, but since they're both holding their horses back, they go to a wise man and ask him what they should do. After that, the brothers race again — this time at full speed. What did the wise man tell them?

horse race
Alan Crowhurst/Getty Images

Explanation: After they switch horses, whoever wins the race will get the inheritance because they still technically own the losing (i.e., slower) horse.

Source: qweiopasd, Reddit

6. A farmer needs to take a fox, a chicken, and a sack of grain across a river. The only way across the river is by a small boat, which can only hold the farmer and one of the three items. Left unsupervised, the chicken will eat the grain, and the fox will eat the chicken. However, the fox won't try to eat the grain, and neither the fox nor the chicken will wander off. How does the farmer get everything across the river?

Boundary Waters Minnesota Canoeing
Robert Engberg / Flickr

Explanation: The farmer must follow these steps.

1. Take the chicken across the river.
2. Come back with an empty boat.
3. Take the grain across the river.
4. Bring the chicken back.
5. Take the fox across the river.
6. Come back with an empty boat.
7. Take the chicken across the river.

Source: someguyinworld, Reddit

7. If you have a 7-minute hourglass and an 11-minute hourglass, how can you boil an egg in exactly 15 minutes?

egg
Flickr/.Larry Page

Explanation: To boil the egg in exactly 15 minutes, follow these steps.

1. Start both hourglasses as you start boiling the egg.
2. After the 7-minute hourglass runs out, turn it to start it again.
3. Four minutes later, when the 11-minute hourglass runs out, turn the 7-minute hourglass again.
4. Wait for the 7-minute hourglass to run out, which will take another four minutes and get you to exactly 15 minutes of boiling time.

Source: DarylHannahMontana, Reddit

8. You are walking down a road and come to a fork. One path leads to certain death; the other leads to eternal happiness. You don't know which is which. In the middle of the fork, you come across two brothers who know which road is which. One brother always tells the truth and the other always lies. You can only ask them one question. How would you determine which road to take?

fork in the road
SaceyK Photography/Shutterstock

Explanation: Let's say the path on the right leads to eternal happiness. After you ask your question, both brothers will tell you the exact same thing: "He would say the left path leads to eternal happiness."

As Reddit user OnscreenForecaster explained, "In either case ... you would pick the opposite of what they both say because one is telling the truth about it being a lie, and one is lying about it being the truth."

Source: SneeKeeFahk, Reddit

9. What is next in this sequence of numbers: 1, 11, 21, 1211, 111221, 312211, ______?

Man writing in notebook
David Ramos/Getty Images

Explanation: Each sequence of numbers is a verbal representation of the sequence before it. Thus, starting with 1, the next sequence would be "one one," or "11." That sequence is followed by "two one," or "21," and so on and so forth.

Still confused? Here's a good explanation by Reddit user hankthetank921:

The first number is just ONE (amount) "1" (0-9 numeral). So if you say there's ONE "1" (seriously just say it aloud) the next number would be an 11. Then there are TWO "1's", creating 21. Then ONE "2" and ONE "1" which creates 1,211. Then ONE "1", ONE "2", and TWO "1's" creating 111,221 ... and so on.

Source: arsenal7777, Reddit

10. Four people arrive at a river with a narrow bridge that can only hold two people at a time. It's nighttime and they have one torch that has to be used when crossing the bridge. Person A can cross the bridge in one minute, B in two minutes, C in five minutes, and D in eight minutes. When two people cross the bridge together, they must move at the slower person's pace. Can they all get across the bridge in 15 minutes or less?

Sours: https://www.insider.com/hard-brainteasers-riddles-for-smart-people-2017-9
Riddles with answers - Brain teasers with answers - Easy Riddles - English riddles - Teat your brain

61 Brainteasers for Adults, Kids, and Everyone in Between

Riddle me this: Why do kids love brainteasers? Answer: They supply hours of free entertainment, that challenge us to think outside the box. They also provide a healthy dose of humility when one is finally told the (so obvious!) answer. But brainteasers are the most fun when you — the parent — are asking them. Riddles and brainteasers allow you to feel much smarter than you really are as your kid struggles to come up with an answer. There’s no better way to pass the time or to get your brain crackling with energy and smarts. 

Here’s a list of easy-to-remember brainteasers to entertain your kids, and prove, once and for all, that you do have more answers than your children.  

  1. What word begins and ends with an E but only has one letter?
    An envelope.
  2. What type of cheese is made backward?
    Edam.
  3. I’m tall when I’m young and I’m short when I’m old. What am I?
    A candle.
  4. In a one-story pink house, there was a pink person, a pink cat, a pink fish, a pink computer, a pink chair, a pink table, a pink telephone, a pink shower — everything was pink! What color were the stairs?
    There weren’t any stairs, it was a one-story house.
  5. Who is bigger: Mr. Bigger, Mrs. Bigger, or their baby?
    The baby, because he is a little bigger.
  6. Mike is a butcher. He is 5-foot-10-inches tall. What does he weigh?
    Meat.
  7. What are the next three letters in the following sequence? J, F, M, A, M, J, J, A, __, __, __
    S, O, N. The sequence is the first letter of the months of the year. September, October, and November are the next in the sequence.
  8. Before Mt. Everest was discovered, what was the highest mountain in the world?
    Mt. Everest. It was still the highest in the world. It just had not been discovered yet!
  9. You are driving a bus. At the first stop, two women get on. At the second stop, three men get on, and one woman gets off. At the third stop, three kids and their mom get on, and a man gets off. The bus is grey, and it is raining outside. What color is the bus driver’s hair?
    Whatever color your hair is! Remember, you are the bus driver!
  10. Imagine that you are in a boat, in the middle of the sea. Suddenly, you are surrounded by hungry sharks, just waiting to feed on you. How can you put an end to this?
    Stop imagining!
  11. When you have me, you immediately feel like sharing me. But, if you do share me, you do not have me.
    A secret.
  12. What can you hold without ever touching or using your hands?
    Your breath!
  13. First, I threw away the outside and cooked the inside. Then I ate the outside and threw away the inside. What did I eat?
    Corn on the cob.
  14. A lift is on the ground floor. There are four people in the lift, including me. When the lift reaches the first floor, one person gets out and three people get in. The lift goes up to the second floor, two people get out six people get in. It then goes up to the next floor up, no one gets out, but 12 people get in. Halfway up to the next floor, the cable snaps, and the lift crash to the floor. Everyone else dies in the lift. How did I survive?
    I got out on the second floor!
  15. A man left home running. He ran away and then turned left, ran the same distance, and turned left again, ran the same distance, and turned left again. When he got home, there were two masked men. Who were they?
    The catcher and the umpire.
  16. What words are pronounced differently by merely capitalizing the first letter?
    There are several, and there could be more: 1. job, Job; 2. herb, Herb; 3. polish, Polish
  17. What can be seen once in a minute, twice in a moment, and never in a thousand years?
    The letter M.
  18. Which tire doesn’t move when a car turns right?
    The spare tire.
  19. What gets wetter the more it dries?
    A towel.
  20. The more you take out of it, the bigger it becomes. What is it?
    A pit.
  21. What can travel around the world while staying in one corner?
    A stamp.
  22. What is at the end of a rainbow?
    The letter W.
  23.  How many months have 28 days?
    All 12 months.
  24. Railroad crossing, watch out for cars. Can you spell that without any Rs?
    T-H-A-T.
  25. Two mothers and two daughters went out to eat. Everyone ate one burger, yet only three burgers were eaten in all. How is this possible?
    They were a grandmother, mother, and daughter.
  26. A man was taking a walk outside when it started to rain. The man didn’t have an umbrella, and he wasn’t wearing a hat. His clothes got soaked, yet not a single hair on his head got wet. How could this happen?
    The man was bald.
  27. How many seconds are there in a year?
    Twelve. January 2nd, February 2nd, March 2nd…
  28. You walk across a bridge and you see a boat full of people, yet there isn’t a single person on board. How is that possible?
    All the people on the boat are married.
  29. Beth’s mother has three daughters. One is called Laura, the other one is Sarah. What is the name of the third daughter?
    Beth.
  30. What’s full of holes but still holds water?
    A sponge.
  31. How can you throw a ball as hard as you can, only to have it come back to you, even if it doesn’t bounce off anything?
    Throw the ball straight up in the air.
  32. I am an odd number. Take away one letter and I become even. What number am I?
    Seven (take away the “s’”and it becomes “even”).
  33. What never asks questions but is often answered?
    A doorbell.
  34. What belongs to you but other people use it more than you?
    Your name.
  35. I have a large money box, 10 inches wide, and 5 inches tall.  Roughly how many coins can I place in my empty money box?
    Just one, after which it will no longer be empty.
  36. What does this mean? I RIGHT I
    Right between the eyes.
  37. What five-letter word becomes shorter when you add two letters to it?
    Short.
  38. Which travels faster? Hot or Cold?
    Hot. You can catch a cold
  39. Jimmy’s mother had four children. She named the first Monday. She named the second Tuesday, and she named the third Wednesday. What is the name of the fourth child?
    Jimmy! Jimmy’s mother had four children.
  40. What is special about the words: job, polish, herb?
    They are all pronounced differently when the first letter is capitalized.
  41. Give me food, and I will live; give me water, and I will die. What am I?
    Fire.
  42. What goes on four feet in the morning, two in the afternoon and three in the evening?
    A human.
  43. Peter’s father has five sons. The names of four sons are Fefe, Fifi, Fafa and Fufu respectively. What is the name of the fifth son?
    Peter.
  44. What’s full of holes but still holds water?
    A sponge.
  45. What flies without wings?
    Time.
  46. Turn me on my side and I am everything. Cut me in half and I am nothing. What am I?
    The number 8.
  47. What has cities, but no houses; forests, but no trees; and water, but no fish?
    A map.
  48. What has to break before you can use it?
    An egg. 
  49. What is the one question you can never answer?
    “Are you asleep yet?”
  50. What’s the one thing you can break without ever touching it?
    A promise.
  51. What goes up but never comes down?
    Your age.
  52. I shave every day, but my hair only grows longer. What am I?
    A barber.
  53. You walk into a room, and on a table, there’s a match, a lamp, a candle and a fireplace. What would you light first?
    The match.
  54. A man dies of old age on his 25th birthday. How?
    He was born on February 29.
  55. What can’t talk but will respond when you speak to it?
    An echo.
  56. The more of this there is, the less you see. What is it?
    Darkness.
  57. I follow you all the time, but you can never catch or touch me. What am I?
    Your shadow.
  58. What’s clean when it’s black and white when it’s dirty?
    A chalkboard.
  59. What has 88 keys but can’t open a single lock?
    A piano.
  60. What gets bigger the more you take away?
    A hole.
  61. Where does today come before yesterday?
    A dictionary.

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Sours: https://www.fatherly.com/play/37-brain-teasers-for-adults-kids-and-everyone-in-between/

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Will you eat. And what to eat. I put out fish and rice.



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