Brain Teaser Questions

What is a Brain Teaser Question?

Brain teaser questions require you to answer an unusual or abstract question, developing a suitable answer based on logic, analysis and hypothesis. They are used to assess your capability to solve a complex problem via a clear thought process. In the majority of cases, you are not expected to reach a perfectly correct answer - and in some instances the interviewer won’t know the correct answer either.

Employers who use the brain teaser questions are more interested in your methodology and creativity. If you struggle with a brain teaser question, then it may indicate (not always) that you could struggle with the role once appointed.


Why do Interviewers use Brain Teaser Questions?

Brain teaser questions are incorporated into the interview process at many leading organisations, usually for positions where candidates need to have an aptitude for solving technical issues or complex problems. The questions are designed to make you think on your feet and when incorporated into an interview situation, they present an even bigger challenge. Knowing what brain teaser questions test and how to approach them will allow you to handle them much better in a real interview situation.

Typically, brain teaser questions will not be related to the job you are applying for. You may be thinking: then why include them at all?

The answer is that businesses use them as a method to review your analytical skills and capacity to reach a logical solution under pressure. Questions are developed to encourage you to think through a query and then use your reasoning skills to determine a response, while remaining calm and measured. The interviewer will be looking to see how you manage the process and reach your answer, not necessarily whether the answer that you give is the correct one.

Brain teaser questions are often asked because the standard interview questions are rehearsed so much it can be difficult for recruiters to really assess the specific skills of candidates. An unexpected brain teaser question can reveal a lot more about a candidate's general intelligence. As such, it can be an effective method to filter applicants.


Brain Teaser Interview Questions

Brain teaser interview questions: designed to make you do expressions like this.


What Qualities do Brain Teaser Questions Test?

Businesses use brain teaser activities to assess the following characteristics:

Your Thought Process

Thinking things through is of utmost importance in some roles. Technical jobs, for example, often require you to approach certain activities with diligence before you take action. If you can easily provide an explanation as to how you arrived at your recommendations, you should be able to handle brain teasers with relative ease.

Identifying Relevant Information

Sometimes the answer to a brain teaser is fairly obvious. They just require you to look at the question and provide the answer without looking into it too much. One of the skills that employers look for is whether you can review information quickly and provide a solution based on the critical information therein.

Response to Uncertainty

Brain teaser questions present something that is unfamiliar. Embrace that and stay calm. Don't rush to answer the question immediately; the interviewers will expect you to take time to consider your response and will be examining how you approach the situation.

Confidence

Working effectively in a stressful situation is something that you may experience in a number of different roles. Through brainteaser questions, employers may want to determine how well you cope under pressure. Approaching the brain teaser with confidence will give the interviewer confidence in you as a potential employee.

Communication

A candidate's ability to communicate clearly and concisely is a major plus point for every employer. But you may be expected to take this one step further and communicate opinions and solutions persuasively to the interviewer. Adequate interview preparation is the key here: you need to research the company in detail, so that you can put together unique and well thought-out answers that will impress.

Solving Problems

How quickly can you solve a problem when you are presented with something out of the ordinary? The brain teaser questions will look at your ability to resolve problems, deploy critical thinking and analytical capabilities to devise a creative solution in a short space of time.


Which Companies Routinely use Brain Teasers?

Certain roles - such as engineers, advanced technicians or even marketing managers - are more likely to be the target of brain teaser questions. Organisations such as Facebook, Google, GlaxoSmithKline, Rolls Royce and Goldman Sachs frequently use them in roles for software engineers and other technical roles, or for other positions where you will be required to use advanced problem-solving capabilities on a regular basis.

That said, there has been a steady decline in the use of brain teaser questions in recent years. Some companies have phased them out completely, replacing them with alternative activities such as an in-tray exercise or other aptitude tests.


How to Approach Brain Teaser Questions

While there is no right or wrong answer to many of the common brain teaser questions, you can perfect your technique so you can provide an appropriate response without panicking. The following strategies will help you answer brain teaser questions with confidence:

  • Think about the question. When the interviewer reads out the question, don’t be tempted to give the first answer that you think of. Take some time to consider what they have said and plan in your head how you will start to structure your answer.
  • Clarification. If you are not sure about something, ask for clarification. Failing to understand the question can result in you completely misinterpreting it or providing an inaccurate answer. See if there is additional information that the interviewer can provide. They may actually be waiting for you to ask for further clarification as part of the question. If the interviewer cannot provide any further information, they will certainly tell you as much.
  • Follow through logically. Begin your answer with a logical sequence of events, basing your response on assumptions or estimates if required. Place emphasis on your thought process rather than the final answer.

Tips for Answering Brain Teaser Questions

Attending an interview is daunting enough, without having to worry about the dreaded brain teaser which may come unexpectedly. Bear in mind these tips:

  1. Take a pen and paper into the interview. The majority of interviewers allow this, particularly when solving a brain teaser question, but always ask if you can use it before the interview begins. If permitted, while the interviewer is asking you the question, jot down some brief notes that may help you with your thought pattern and response.

  2. Relax. Getting flustered by these questions won’t solve anything, so try to stay as calm as possible.

  3. Listen carefully. Pay attention to the interviewer when they are explaining the question

  4. Any answer is better than none. If you can’t figure out the answer, just provide a response as best you can.

  5. Explain. If you are working out the answer in your head, think out loud. Tell the interviewer the process of your thoughts and how you are reaching a decision. If, however, you suddenly reach another answer during your thought process, tell the interviewer as they will also be looking for someone who can devise multiple scenarios to real business issues.


Sample Brain Teaser Questions (By Category)

Although you may be asked different brain teaser questions depending on the role that you are applying for, whether that's software engineer or product manager, many of the questions will be based on the same sort of reasoning process. Broadly speaking, there are three different categories of brain teaser questions: riddles, 'how many' questions. or numeracy questions.

Brain Teasers Based Around Riddles

With riddle brain teasers, interviewers will present you with a very peculiar situation and ask you what you would do. The interviewer is looking for your ability to think quickly and deploy skills in problem-solving and creativity to see what kind of solution you provide. Google was renowned for asking these sorts of brain teaser questions, as was Microsoft. One of Microsoft’s frequent brain teaser questions was to ask candidates how they could move Mount Fuji. The answer of course, is that it would be impossible to move a mountain but the interviewer would be looking to see how well you answered the riddle and what your reasoning process was.

Although many firms (including Microsoft and Google) have now ceased asking these sorts of questions, don’t be surprised if you come across similar ones at other large employers. Even if you are really struggling to provide an answer, don’t let it put you off or reduce your confidence. Other riddle questions we've come across include:

  • Why are manhole covers round?
  • How can you tell if the light inside your refrigerator is on or not?
  • How do you know if anything your brain is comprehending is real - could it all just be in your brain?

Answers: There's no definite answer for any of these. You could argue that manhole covers are round so they can be rolled easily into place and won't fall down the hole. Equally, you can determine if your fridge light is on by using a camera or testing the sensor with your thumb.


Brain Teaser Questions

So...why are these round and not square?


Brain Teasers based around ‘How Many?’

Questions that ask ‘how many’ will require candidates to think through a problem logically. Unless you have exceptional skills in general knowledge, you will have to make some assumptions or estimations to provide an answer. Typical questions include:

  • How many petrol stations are there in the UK?
  • How many boxes of breakfast cereal are sold in the US every year?
  • How many times heavier than a goldfish is a blue whale?

Think out loud, and write down your notes as you go. Make sure that your estimates are being calculated logically (even if they are wildly off).


Numerical Brain Teasers

In certain careers, you will be expected to use your numerical skills on a regular basis. The interviewer may throw in a numerical brain teaser to present something unexpected. Commonplace in finance or accounting roles, this type of brain teaser is provided in the format of a story or presents a sequence of numbers. It is your task to tell the interviewer what comes next and provide reasons for how you reached this decision. Examples of this are:

  • Two mothers and two daughters sit down to eat eggs for breakfast. They ate three eggs and each person at the table ate an egg. Explain how.
  • A shop owner can fit 8 large boxes or 10 medium boxes into a container for delivery. In one consignment, he distributes a total of 96 boxes. If there are more large boxes than medium boxes, how many cartons did he ship?
  • How can you add eight eights to reach 1000?

Answers:

  1. One of the mothers is also a grandmother. Therefore the other mother is both a daughter and a mother to the granddaughter.
  2. 11 containers in total. There are 7 large boxes (7 * 8 = 56 boxes) and 4 medium boxes (4 10 = 40 boxes).
  3. Try 888 + 88 + 8 + 8 + 8 = 1,000.

Summary

Although brain teaser questions are now being phased out by some companies, some organisations still use them as a way to test your skills and to throw something unexpected into the interview process. Often used as a method of filtering candidates, brain teaser questions can take a number of different forms, from riddles and ‘how many’ questions through to those which are based on a story or situation.

The best way to approach them is to take your time, think about what is being asked of you and use your reasoning skills to work through to the answer. Interviewers are usually more concerned about how you reach the answer rather than you getting the correct answer (many of them won’t even know the right answer themselves). Brain teasers are a great way to assess your skills in problem solving, communication, creativity and your ability to develop one or more viable solutions to a problem, so make sure that you demonstrate this when providing your response.


Further reading

There are a number of online resources where you can find additional information on brain teasers. If you are applying to a company and you are confident that you will be asked one of these questions, or even if you have a slight inkling that one may appear at some point, it is always best to prepare and not be asked, than fail to prepare and be asked.