How to Approach Brainteasers in a Consulting Interview

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Last Updated on February 7, 2024

Brainteasers have long been a staple in consulting interviews, serving as a valuable tool for assessing a candidate’s problem-solving skills, mental agility, and ability to think outside the box. As consultants are often required to tackle complex problems and provide innovative solutions for clients, the ability to excel at brainteasers is a critical attribute that top-tier consulting firms seek in their prospective hires.

In this article, we will delve into the world of brainteasers in consulting interviews, exploring their various types and the reasons behind their significance. We will also provide practical tips on how to prepare for these challenging questions, along with strategies for tackling them effectively. Finally, we will discuss the importance of communication during the brainteaser-solving process, offering advice on how to present your thought process and solutions clearly and confidently.

What is a Brainteaser?

A brainteaser is a puzzle or riddle that is designed to test your problem-solving skills and your ability to think logically and creatively. Brainteasers can come in many different forms, including math problems, logic puzzles, riddles, and other types of challenges. They are often used in interviews and other situations where employers are looking for candidates who can think on their feet and come up with creative solutions to challenging problems. Some common examples of brainteasers include questions like: “How many golf balls can fit in a school bus?” or “If you have three ropes that take 60 minutes to burn, how long will it take to burn just one rope?”


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Understanding Brainteasers in Consulting Interviews

Types of brainteasers commonly encountered

Brainteasers in consulting interviews can be categorized into several types, each designed to test different aspects of a candidate’s problem-solving abilities. Some common types include:

Logic and reasoning puzzles

These brainteasers often involve puzzles or riddles that require the application of logical thinking and deductive reasoning to arrive at the correct answer.

Examples of logic brainteasers:

The Three Light Bulbs

In a room, there are three light bulbs, and outside the room, there are three switches, each corresponding to one of the light bulbs. You are allowed to go into the room only once, and you cannot see the light bulbs from outside. You need to figure out which switch corresponds to which light bulb. You can turn the switches on and off as many times as you want, but you can only enter the room once. How do you determine which switch corresponds to which light bulb?

The Colored Hats

Four friends, Alice, Bob, Carol, and Dave, are captured by a mysterious figure who forces them to play a game. They are each given a hat to wear, and they are told that the hats come in two colors: black and white. They can see each other’s hats but not their own. They are lined up in a straight line, facing forward, with Alice at the back, Bob in front of Alice, Carol in front of Bob, and Dave at the very front. Alice can see both Bob and Carol’s hats, Bob can see only Carol’s hat, and Carol can see only Dave’s hat. Dave cannot see any hats. The mysterious figure tells them that at least one of them is wearing a black hat. They must each guess the color of their own hat, and they can only say “black” or “white.” If at least one of them guesses correctly, they will all be set free. If they all guess incorrectly, they will be doomed. They are not allowed to communicate in any way other than saying their guesses. The friends are given a moment to strategize before they start guessing. What strategy should they use to maximize their chances of being set free?

Math-based problems

These questions involve numerical data or calculations, testing a candidate’s quantitative abilities and attention to detail.

Examples of math brainteasers:

The Missing Number

Consider the following sequence of numbers:

1, 2, 4, 8, 16, 32, 64, _, 256

There is a number missing in the sequence. However, this sequence does not follow the usual pattern of doubling each number. Your task is to figure out the rule for this sequence and determine the missing number.

The Age Puzzle

A father says to his son, “Seven years ago, I was five times as old as you were then. In three years, I will be twice as old as you will be at that time.” How old are the father and the son currently?

Estimation and guesstimate problems

Candidates are asked to make educated guesses or estimations based on limited information, testing their ability to think critically and analyze data. This is more related to market sizing and estimation questions, which we cover here.

Pattern recognition and sequencing puzzles

These brainteasers involve identifying patterns or sequences in a given set of data, and testing a candidate’s analytical and observation skills.

Examples of pattern recognition brainteasers:

Shape Sequence

Consider the following sequence of shapes:

Circle, Square, Triangle, Circle, Square, Triangle, Circle, _, _

Determine the next two shapes in the sequence based on the pattern.

Number and Letter Sequence

Examine the following sequence of numbers and letters:

1A, 2B, 3C, 4D, 5E, _, _

Identify the pattern and determine the next two elements in the sequence.

Lateral thinking puzzles

These questions encourage thinking outside the box, requiring candidates to find creative solutions or see problems from a different perspective.

Examples of lateral thinking brainteasers:

The broken clock

A clock with a broken minute hand shows the correct time twice a day, at noon and midnight. However, the hour hand is intact and working perfectly. One day, the clock’s owner looks at the clock and notices that, although the minute hand is broken, the clock is showing the correct time. He then leaves the room and comes back later. Without knowing how much time has passed, how can he be sure that the clock is showing the correct time again?


How many bananas fit into a SpaceX rocket?

Why consulting firms value brainteaser-solving skills

Consulting firms highly value brainteaser-solving skills for several reasons:

  1. Problem-solving abilities: Brainteasers are an effective way to assess a candidate’s ability to analyze complex problems, think critically, and develop innovative solutions – skills that are essential in the consulting profession.
  2. Mental agility: Tackling brainteasers requires mental flexibility and adaptability, qualities that are crucial for consultants who must quickly adapt to new situations and challenges.
  3. Creativity and lateral thinking: Brainteasers often demand unconventional thinking and creativity, which consultants need when developing unique solutions for clients.
  4. Time management and composure: Brainteasers test a candidate’s ability to perform under pressure and manage time efficiently, mirroring the fast-paced and high-stakes environment of consulting work.
  5. Communication skills: Presenting a clear and concise solution to a brainteaser demonstrates a candidate’s ability to communicate effectively, a vital skill for consultants who must regularly explain their analyses and recommendations to clients.

Who employs brainteasers?

Brainteasers have become less relevant in today’s consulting recruiting and interview market since they are quite detached from actual business problems and do not allow for objective evaluation metrics and comparison of candidates.

Top-tier firms such as McKinsey, BCG, and Bain rarely (if at all) employ these types of questions. However, you will likely come across brainteasers in tier-2 firms, the Big 4, and boutique consulting firms, as well as interviews for industry roles.

Preparing for Brainteasers

Developing mental agility and problem-solving skills

To excel at brainteasers in consulting interviews, it’s essential to develop your mental agility and problem-solving skills. You can enhance these abilities by:

  1. Engaging in activities that challenge your brain, such as puzzles, Sudoku, or chess.
  2. Practicing mental math and improving your numerical proficiency.
  3. Regularly reading about diverse topics and industries to broaden your knowledge base and enhance critical thinking.

Familiarizing yourself with common brainteaser categories

Understanding the types of brainteasers you may encounter in consulting interviews is crucial for effective preparation. Familiarize yourself with the common categories mentioned earlier, and research examples of each type to gain a deeper understanding of their structure and requirements.

Practicing with a range of brainteasers

To build your confidence and proficiency in solving brainteasers, practice is key. Follow these steps to maximize your preparation:

  1. Start with simpler brainteasers to warm up and gradually progress to more complex ones.
  2. Allocate time for daily practice, simulating interview conditions by setting time limits for each brainteaser.
  3. Review your solutions and compare them with the correct answers to identify areas for improvement.
  4. Seek feedback from peers or mentors to refine your problem-solving approach and communication skills.
  5. Rotate through the different categories of brainteasers to ensure a well-rounded preparation.

Strategies for Tackling Brainteasers

Analyzing the question and identifying key elements

Before attempting to solve a brainteaser, take a moment to analyze the question and identify the key elements. This will help you to understand the problem better and enable you to determine the most effective approach. Carefully read the question, break it down into smaller parts, and determine what information is provided and what is required.

Structuring your approach using relevant frameworks

Having a structured approach when solving brainteasers can help you stay organized and focused. Depending on the type of brainteaser, consider using relevant frameworks, such as MECE (Mutually Exclusive, Collectively Exhaustive) or SCQA (Situation, Complication, Question, Answer). These frameworks can help guide your thought process and ensure a comprehensive solution.

Applying critical thinking and logical reasoning

Once you’ve analyzed the question and chosen a framework, apply critical thinking and logical reasoning to work through the problem. Assess the information provided, identify assumptions or constraints, and test your hypotheses. Be prepared to adjust your approach as new insights emerge, and don’t be afraid to think outside the box.

Managing time efficiently and maintaining composure

Brainteasers can be time-sensitive, so it’s crucial to manage your time efficiently. Allocate your time wisely, avoiding getting stuck on one aspect of the problem for too long. If you find yourself struggling, take a brief pause to regroup and consider alternative approaches. Remember to maintain your composure during the process, as consulting interviews often test your ability to handle pressure and think on your feet.

How can you approach a brainteaser?

  1. Take a moment to understand the question: Before you start trying to solve the brainteaser, take a moment to read the question carefully and make sure you understand what it is asking. If you are unsure what the question is asking, ask for clarification from the interviewer.
  2. Break the problem down into smaller parts: Once you understand the question, try to break the problem down into smaller parts. This can help you simplify the problem and make it easier to solve. For example, if the brainteaser is a math problem, you might start by solving a simpler version of the problem, or by looking for patterns or relationships in the data.
  3. Use logic and creativity: As you work on the brainteaser, use your logic and creativity to find solutions. This might involve trying different approaches, making educated guesses, or using your knowledge of math, science, or other subjects to help you solve the problem.
  4. Test your solution: Once you have come up with a potential solution to the brainteaser, test it to see if it is correct. If your solution does not work, try to figure out why and adjust your approach accordingly.
  5. Be persistent and don’t give up: Brainteasers can be difficult, and it is normal to struggle when trying to solve them. If you get stuck, don’t give up. Instead, take a break, clear your head, and come back to the problem with a fresh perspective.

Overall, the key to solving a brainteaser is to approach it systematically, use your logic and creativity, and be persistent. By following these steps, you can improve your chances of finding a solution to the brainteaser.

Tips for Effective Communication During Brainteaser-Solving

Clearly articulating your thought process

As you work through a brainteaser, clearly articulate your thought process to the interviewer. This demonstrates your ability to communicate complex ideas effectively, which is crucial in consulting roles. Speak slowly and confidently, explaining each step of your approach and the rationale behind it.

Demonstrating active listening and adaptability

Show the interviewer that you are actively listening and open to feedback by maintaining eye contact and acknowledging any input they provide. Be prepared to adapt your approach if they offer suggestions or insights, showcasing your flexibility and willingness to learn.

Seeking clarification when needed

If you encounter any ambiguities or uncertainties in the brainteaser, don’t hesitate to ask the interviewer for clarification. This shows your attention to detail and commitment to finding the correct solution. Additionally, it demonstrates your ability to communicate effectively and collaborate with others.

Summarizing your solution concisely

Once you’ve arrived at a solution, summarize your findings concisely for the interviewer. Highlight the key steps you took, the insights you gained, and the final outcome. Keep your explanation brief and to the point, showcasing your ability to present complex information in a clear and easily digestible manner.

Example Brainteaser from a Real MBB Case Interview

Imagine that you are standing on a beach and looking out at the ocean. Suddenly, you see a boat in the distance, moving towards you at a steady speed. You know that the boat is exactly 100 meters long, but you cannot see how far away it is because the water is choppy and the boat is bobbing up and down.

Without using any additional tools or instruments, how can you determine the distance between you and the boat?

An example of a brainteaser

To solve this brainteaser, you could use the following approach:

  1. Understand the problem: The problem is asking you to determine the distance between you and the boat without using any additional tools or instruments.
  2. Break the problem down into smaller parts: To solve the problem, you will need to find a way to measure the distance using only information that you have available to you.
  3. Use logic and creativity: One way to solve the problem is to use the boat’s length as a reference point. If you know that the boat is 100 meters long, you can measure the distance to the boat by timing how long it takes for the boat to pass you.
  4. Test your solution: To test your solution, you could stand on the beach and time how long it takes for the boat to pass you. For example, if the boat takes 20 seconds to pass you, you can calculate the distance to the boat using the formula: distance = speed x time. In this case, if the boat is moving at a speed of 5 meters per second (100 meters / 20 seconds), the distance to the boat would be 100 meters.
  5. Be persistent and don’t give up: If your initial solution does not work, don’t give up. Instead, try to think of other ways to solve the problem, such as using the boat’s size as a reference point, or using the angle of the boat relative to the horizon to calculate the distance.

By following this approach, you can solve the brainteaser and determine the distance between you and the boat. For more practice, check out the following 15 FREE exercises here.

Keep up the work

Recap of key takeaways

In this article, we’ve explored the importance of brainteasers in consulting interviews and the various types of brainteasers commonly encountered. We’ve also discussed effective preparation strategies, such as developing mental agility, familiarizing yourself with common brainteaser categories, and practicing with a range of examples. Additionally, we’ve shared valuable tips for tackling brainteasers, including analyzing the question, structuring your approach, applying critical thinking, and managing time efficiently. Finally, we’ve provided guidance on effective communication during the brainteaser-solving process.

Practice to improve

As with any skill, mastering brainteasers requires dedication and consistent practice. By following the advice and strategies outlined in this article, you’ll be well on your way to excelling at brainteasers in consulting interviews. Stay committed to your preparation, continuously refine your problem-solving skills, and embrace every opportunity to learn and grow. With hard work and perseverance, you’ll be ready to impress interviewers and secure your dream consulting role.

How Can You Practice Brainteasers?

Introducing the Ultimate Consulting Interview Brainstorming Course: Mastering Brainteasers

Prepare for top-tier consulting firm interviews with our comprehensive Consulting Interview Brainstorming Course, designed to make you a brainteaser-solving expert and give you the edge to secure your dream consulting role.

You can find more information about the course here.

Course Overview

This extensive program delves into various brainteaser types, covering everything from preparation strategies to tailored approaches for tackling complex problems.


  1. In-depth brainteaser explanation: Understand logic, patterns, and nuances of different brainteaser categories, building a strong problem-solving foundation.
  2. Comprehensive preparation strategies: Optimize your preparation process with effective methods that build confidence and enhance mental agility.
  3. Personalized problem-solving approaches: Develop customized strategies for each brainteaser type, tackling even the toughest challenges.
  4. 155 practice examples from simple to hard: Progressively build skills with a wide range of brainteasers, complete with detailed explanations and solutions.
  5. Expert tips and guidance: Benefit from seasoned instructors who share invaluable insights and advice to help you stand out in a competitive field.

By the end of this course, you’ll master the art of solving brainteasers, impress your interviewers, and pave your way to a successful consulting career.

Ace consulting brainteasers with our dedicated preparation packages.

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