Get Ready for Brainteasers of Any Kind

Aunt Annie
Brainteaser: Aunt Annie
After visiting my Great Aunt Annie, I travelled home in her old jalopy. The car was old and battered, it had a leak from the petrol tank, and I was stuck in second gear. This meant that I could only travel along at a steady 30 miles per hour and managed a paltry 20 miles per gallon of fuel. At the start of the journey I had placed exactly 10 gallons of fuel into the tank. I knew though, that the fuel tank lost fuel at the rate of half a gallon per hour. Just as I arrived home, the car stopped because it had run out of fuel and I had only just made it. How far was it from my Great Aunt's to my home?
Countersign
Brainteaser: Countersign
Two spies want to get into an enemy's military base. In order to pass the guard they have to give the correct countersign at the gate. So they wait hidden nearby the gate so that they will overhear the countersign from other soldiers. A soldier arrives and the guard gives the sign: "six". The soldier answers "three". The guard lets him pass. Another soldier arrives. The guard says "twelve" and the soldier gives the answer "six". The guard lets him pass. So, the first spy goes to the gate and the guard says "ten". The spy, being sure to know the answer, says "five". Immediately, the guard shoots him. The other spy, who saw that his colleague had been killed after giving the wrong countersign, had now understood what the right answer should have been, whatever the guard's sign was. So, he walks to the gate and the guard says "eight". The spy answers correctly and the guard lets him in. What was the answer that the spy gave?
Climb up the well
Brainteaser: Climb up the well
A man accidentally fell down 30 metres into a well and survived. His friend gives him a rope. Every 5 minutes, the man is able to climb up 3 metres, but always slips back 1.5 metres. How much time will it take him to climb up the well?
The color of the horse
Brainteaser: The color of the horse
I have a horse. Do you know what color it is? Allan said, "I guess it is not black". Brian said, "It is either brown, or gray". Charlie said "I know it is brown". I said, "At least one of you is right and at least one of you is wrong." What is the color of my horse if the color is one of the above?
Brainteasers are a helpful exercise to train your logical thinking.
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The pool
Brainteaser: The pool
A pool has four taps. The first tap takes two days to fill the pool, the second tap three days, the third four days and the last one only 6 hours. How long will it take to fill the pool using all 4 taps at once?
Genius
Brainteaser: Genius
Can you find out the smallest number that can be conveyed as the sum of three squares in three unique ways?
The Scientists and the Fence
Brainteaser: The Scientists and the Fence
A farmer challenges an engineer, a physicist, and a mathematician to fence off the largest amount of area using the least amount of fence. The engineer made his fence in a circle and said it was the most efficient. The physicist made a straight long fence and said that the length was infinite. Then he said that fencing half of the Earth was best. The mathematician laughed at the others and with his design, beat the others. What did he do?
The Island
Brainteaser: The Island
James visited an island. There were 2 tribes living on this island. The people from the tribe in the East always tell lies, while those from the West always tell the truth. James and his local tour guide ran into a guy. He told his tour guide to find out where the guy is from. The tour guide asked the guy and translated the answer for James: "He lives over in the West." Which part of the island does the tour guide come from?
Numbers Map
Brainteaser: Numbers Map
Arrange the numbers from 1 to 8 in the following sequence. a b c d e f g h Each number must not be diagonally or directly adjacent to any number directly before or after it. For example, 2 can only be placed in one spot. 2 x x x x 1 x x
Alphabet Riddle
Brainteaser: Alphabet Riddle
Which letter of the alphabet is a tool?
From 0 to 120
Brainteaser: From 0 to 120
Find a way by which you can get a total of 120 by using five zeros 0,0,0,0,0 and any one mathematical operator.
4566
Brainteaser: 4566
What digit should appear after this list of numbers? 4 5 6 6 5 4 4 2 ?
The dog
Brainteaser: The dog
A girl, a boy, and a dog start walking down a road. They start at the same time, from the same point, in the same direction. The boy walks at 5 km/h, the girl at 6 km/h. The dog runs from boy to girl and back again with a constant speed of 10 km/h. The dog does not slow down on the turn. How far does the dog travel in 1 hour?
Code in the Cold
Brainteaser: Code in the Cold
Last winter I found myself locked out of my house because I couldn’t remember the 5-digit code to open the garage door. I used the following facts to get inside. 1. The second and third digits add up to 9. 2. The first digit is equal to the second digit cubed. 3. The sum of the third and fifth digits is the smallest number with exactly five divisors. 4. The fourth digit is equal to 6 times the second-to-last digit. 5. None of the digits repeat. What was the code?
How many monkeys?
Brainteaser: How many monkeys?
Suppose 8 monkeys take 8 minutes to eat 8 bananas. (a) How many minutes would it take 3 monkeys to eat 3 bananas? (b) How many monkeys would it take to eat 48 bananas in 48 minutes?
Which word?
Brainteaser: Which word?
Which word looks the same upside down and backwards?
How can this be?
Brainteaser: How can this be?
A woman shoots her husband. Then she holds him under water for over 5 minutes. Finally, she hangs him. But 5 minutes later they both go out together and enjoy a wonderful dinner together. How is this possible?
Money change
Brainteaser: Money change
What is the largest amount of money that you can possess in change and still if someone asks you for a dollar, you won't be able to give?
Number Series
Brainteaser: Number Series
You and I will take turns saying numbers. The first person will say a number between 1 and 10. Then the other person will say a number that is at least 1 higher than this number and at most 10 higher. We will keep going back and forth in this way until one of us says the number 50. That person wins. It's your turn to start. What number should you start with?
A Duck
Brainteaser: A Duck
There are two ducks in front of a duck, two ducks behind a duck and a duck in the middle. How many ducks are there in total?
Time intervals
Brainteaser: Time intervals
A cyclist rides along a railway embankment where trains commute regularly between two cities. Every 30 minutes a train overtakes the cyclist from behind, every 20 minutes he encounters a train. At what time intervals do the trains commute?

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!