Get Ready for Brainteasers of Any Kind

Candy jar
Brainteaser: Candy jar
You got a jar with two types of candies for Christmas – 20 blueberry and 16 strawberry. You perform the following steps: 1) You take out two candies. 2) If the two candies are of same flavor, you add a blueberry one otherwise, you add the strawberry one. You repeat these two steps till there is just one candy remaining in the jar. Which flavored candy will be left? Also, if you began with 100 blueberry candies and 93 strawberry candies, which flavor would have been the last one to remain?
Bank robbery
Brainteaser: Bank robbery
Lars lost his job a few weeks before Christmas, but did not tell his family. Now, he needs money to buy Christmas presents for his kids. He decides to rob a bank. When he enters the bank, an employee is standing in front of him unarmed. Lars aims a gun at him and asks for the code to open the safe. The employee says, 'The code is different every day but if you hurt me, you will never get to know the code'. Lars pins him down and ties him with a rope. He then inserts the code of the safe and easily takes all the money with him. How did he know the code?
Santa’s little helper
Brainteaser: Santa’s little helper
Santa Claus has a problem. His little helper got really old and does not feel like accompanying Santa on his yearly Christmas journey. Hence, Santa Claus needs to find a new little helper. He summons all inhabitants of Christmas Land and gives one seed to each of them. Then he asks them to plant it. Further he announces that the one with the most beautiful plant will become his new little helper. After a month, all of them are called. Santa Claus looks at all of the plants but announces the girl with an empty pot as the new little helper. Why?
Batteries
Brainteaser: Batteries
It is a snowy and cold night when you meet a sad old man on a sleigh. The man introduces himself as Santa Claus. Apparently one of his reindeers got a cold, and every time it sneezes, Christmas gifts fell off the sleigh. Now all the gifts are spread over a forest nearby. You decide to help Santa Claus collecting the gifts. Before you enter the dark forest you pick up a flashlight and 8 batteries at your brothers house. A few minutes later your brother calls to tell you that four of those batteries are already dead. Your flashlight requires two working batteries to run. What is the least number of pairs you will need to test to guarantee that you can get the flashlight on?
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The Barbershop
Brainteaser: The Barbershop
A young man visits his girlfriend’s family in a small town over Christmas. When they arrive at the small town, his girlfriend asks the man to go to the hairdresser before meeting her family. Since the town is quite small, there are only two barbers in the town – one on the North Street and one on the South Street. The barbershop on the North Street is a mess and the barber has a weird and pathetic haircut. While the barbershop at the South Street is pretty tidy and the barber as well has an impressive haircut. Which barbershop will the man visit for his haircut and why?
The old woman
Brainteaser: The old woman
It is the 2nd of advent, when a charming young lady was approached by a kind looking old woman in a nice restaurant. The old woman said to her, 'You look exactly like my younger daughter. Sadly she passed away a couple of months back. Now I’m spending all this Christmas time without my beloved girl. Could you do me a favor and say 'Goodbye, mother' with a kind smile on your face when I leave? The young lady agreed for the same and said, 'Goodbye, mother' when the old woman left. Soon after, she got the most disengaging shock of her life. Can you guess what the shock was?
Three sisters
Brainteaser: Three sisters
There are three identical triplets sisters. Demi is the oldest of them all and she always speaks truth. Diana is the next one who is a liar always. Drew, the youngest of them all speaks both truth and lies randomly. On Christmas Eve the whole family comes together. The girls’ uncle Victor got each girl a different present. Since the girls look starkly identical, he is not able to recognize them. Thus to clarify, he asks one question to each one of them. He starts with the one standing on the left and asks, 'Which sister is in the middle of you three?' She answers, 'That’s Demi.' Then, he asks the one standing in the middle, 'What is your name?' She answered, 'I am Drew.' Finally he asks the one standing on the right, 'Who is standing in the middle?' She answers, 'She is Diana.' Victor is left baffled. He asks the questions three times and receives different answers every time. Can you tell who is who?
Mulled Wine
Brainteaser: Mulled Wine
On a Christmas market a man went straight towards the mulled wine booth. He asked for a mulled wine from the barman. The barman thought something and then pulled out a pistol from a drawer. He aimed it directly at the man. Why did he do that?
The Christmas gift
Brainteaser: The Christmas gift
A man has two sons. All these years, he has treated them equally and has not put any sort of discrimination between them. As he is very old, he wants to make both of them a special gift for Christmas. The old man owns land that he wants to divide in a way that both sons get a fair piece of land for Christmas. The only problem is that the land is not in any symmetrical shape and thus can’t simply be divided into two equal halves. Can you figure out a method to divide the land without going through all the extensive measurements such that both sons are happy with their share of land?
Christmas Card
Brainteaser: Christmas Card
Lisa got a Christmas card from her brother. On the card it is written: „Solve the following quiz and you will get your Christmas present: What does the following Brain Bat signify? ABCDEFGHIJKLMNOPQRSTUVWYZ QQQQQQQQQQQQQQQQQQQQQQQQQ.“ What is your solution?
Christmas tree balls
Brainteaser: Christmas tree balls
You are given four Christmas tree balls and asked to arrange those balls at a Christmas tree in a manner that the distance between each one of them is exactly equal. How will you do it?
The bloody Christmas dinner
Brainteaser: The bloody Christmas dinner
Old Mrs. Patty holds her yearly Christmas dinner, when suddenly a person lies murdered in her living room. When police arrives, there are six people present in the house who are friends of the victim. The names of the friends are Rohit, Aman, Nick, Gagan and Randy. Near the dead body, they find a few numbers written with blood by the victim on floor. The numbers are 8, 5, 4 and 11. The police arrests one of the friends for the murder. Whom did they arrest and why?
The frozen lake
Brainteaser: The frozen lake
On your Christmas holidays you decide to go ice-skating. Unfortunately you get trapped on the surface of the frozen lake. The surface is so smooth and ideal that there is no friction at all. You can’t make any grip on the ice and no wind is blowing to help you out. You have just a mobile phone with you, which has got no reception disabling you to call for help. How will you plan your escape before you freeze to death on the frozen lake?
The Ski Trip
Brainteaser: The Ski Trip
Alex and Martin are planning on their ski trip between Christmas and New Years Eve. Alex says, "It will be better if we take the train to the hotel. We will reach faster." To this, Martin says, "No. You are wrong. The train stops at halfway to the hotel and then we will have to walk the rest of the way through the snow. We should take the cross-country skis to the hotel directly." Alex says, "You are wrong." Now, Alex takes the train while Martin takes the cross-country skis. The train travels with four times the speed of the skis. Martin on the skis travels at twice the speed of walking. Who do you think will reach the hotel first?
Mrs. Knifflig's daughters Xmas
Brainteaser: Mrs. Knifflig's daughters Xmas
On a snowy winter day it is ringing at Mrs. Knifflig’s door. When she opens the door, Santa Claus is standing in front of her. Apparently, most of his elves got sick. Desperately he tries to find help to pack the entire Christmas gifts. Mrs. Knifflig is not really excited about this idea but is willing to give Santa Claus a chance: “If you are able to guess the ages of my three daughters right, I will help you out. I will give you two hints. First: The product of my daughters’ years of life is 36. Second: If you add the ages of my girls, the sum equals my house number.“ Santa Claus listens carefully but complains that he needs more information to answer the question right. Mrs. Knifflig agrees: “Ok, I will give you one last tip: The oldest of my daughters is at her grandmother at the moment.“ After a little while, Santa Claus gives the right answer. How old are the daughters?
Hilarious facts about Christmas Ville
Brainteaser: Hilarious facts about Christmas Ville
There is a town close to Lapland named Christmas Ville. In that town you can find extremely hilarious facts. None of the residents has 456,789 hairs on their heads. The number of residents is higher than the number of hairs on each of their heads. Can you find out the largest number of residents in such a scenario?
Crossing the candy river
Brainteaser: Crossing the candy river
In Santa Claus’ land of Christmas there is a huge candy river, separating the candy forest from candy town. Especially around Christmas it gets very wild and dangerous to cross. A family of elves is standing on the wrong side of the river. The family includes mom and 2 daughters, dad and 2 sons, a maid and a reindeer. There is a huge candy cane to cross the river, which can hold only two persons at a time (reindeer counts as one person as well). Obviously, the kids can’t operate the candy cane and an adult is needed for that task. Here comes the difficulty: The maid must remain with the reindeer to control it. The dad cannot be left with the daughters without mom, nor can the mother be left alone with the sons without dad. Can you help them cross the candy river?
The wisest elves of Lapland
Brainteaser: The wisest elves of Lapland
Santa Claus calls upon the wisest elves of Lapland to his court. One of them is to be chosen for the advisor rank and thus they shall prove their worth in the test. Santa Claus places a hat on each of their heads. Each one of them can see other two hats but can’t see his own. The hats are either white or black. For a hint, Santa Claus tells them that at least one of them is wearing a black hat. Also the king declares that the test is totally fair for each one of them. Now the first one of them who is able to deduce the color of hat he is wearing will be designated as advisor. Only after a few minutes, one of them was able to deduce the color of his own hat. How?
Travelling Reindeer
Brainteaser: Travelling Reindeer
A reindeer travels the exact same distance every Christmas. Strangely two of his legs travel 40 kilometers and the remaining two travel 41 kilometers. Obviously two reindeer legs cannot be 1km ahead of the other two. The reindeer is perfectly normal. So how can this be true?
Grows Up and Grows down
Brainteaser: Grows Up and Grows down
What grows up while growing down?
Lockers
Brainteaser: Lockers
Suppose you're in a hallway lined with 100 closed lockers. You begin by opening every locker. Then you close every second locker. Then you go to every third locker and open it (if it's closed) or close it (if it's open). Let's call this action toggling a locker. Continue toggling every nth locker on pass number n. After 100 passes, where you toggle only locker #100, how many lockers are open?

Questions

Frequently Asked Questions
We are happy to answer the most frequently asked questions.

Brain teasers in the form of math problems and logic puzzles can still appear in interviews, but they are quite rare. More common now are market sizing guesstimates, such as “How many tennis balls can fit into a smart car?” These questions may also be referred to as brain teasers. In general, brain teasers test your creativity and ability to think outside the box.

Brain teasers are uncommon in interviews, and there is no specific rule regarding when an interviewer may choose to use one. However, they are more typical in final rounds and can be asked either before or after the main case discussion.

Market sizing guesstimates are often referred to as brain teasers as well. They are more common in interviews and consist of questions that ask you to determine a specific quantity, such as “How many golf balls can you fit into a passenger Boeing 747?” These questions test your ability to define a problem, break it down into assumptions, and use math to solve it.

Always prioritize case studies and the personal fit portion in your interview preparation, as these are the crucial aspects of your interview! Once you feel more comfortable with those, you can integrate some brain teaser practice into your preparation. This may give you the advantage you need to stand out among other candidates! You can use our brain teaser library to challenge your creative thinking. Have fun!

Brain Teaser – Challenge Your Logical and Numerical Thinking

A brain teaser is a riddle or puzzle designed to challenge your logical thinking. In interviews, interviewers may use them to gain insights into your logical and creative thinking skills, which are valuable in various careers. The most important aspect here is not just the answer but how you approach the problem. Practice our brain teasers to prepare yourself for any interview situation!