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Why brain teasers are out

First a little exercise to warm up your brain: There are three light switches in the basement, but only one light in the attic. You cannot see the attic from where you are; you may only enter it once and cannot call on any outside help. How do you work out which of the three switches is the right one to switch on the light?
Marcel Hofstetter
Marcel Hofstetter, Talent Sourcing & Relationship Manager
08 March 2021

Confused? It gets even harder when your dream job depends on it, when you have potential new colleagues smiling at you and you only have five minutes to answer. This is an example of a brainteaser, and the question above is of the more harmless variety. An even trickier one, for example, would be asking how many golf balls fit into a Boeing 747 or how many boxes of cornflakes are sold in Switzerland each year. Such questions likely have very little, if anything, to do with your future job. Nevertheless, there are still some interviewers who believe that brainteasers offer a comprehensive insight into the problem-solving skills, intelligence, stress resistance and other attributes of their candidates.


Personally, I believe that such ‘riddles’, as I call them, provide no insights into your relevant experience for the job or your greatest successes and failures (or the lessons learned!), nor do they provide any indication of your ability to work in a team. And since the interviewer is usually more concerned with the approach and thinking than with the correct answer, an evaluation of the solution is always highly subjective. Unless the person opposite you has actually loaded a plane with golf balls and knows the answer. For me, therefore, this begs the question as to whether brainteasers are not also, in fact, partly for the amusement of the interviewer. Which is where, I would argue, the fun really stops.


It is for this reason, and because ‘traditional’ interviews are already stressful enough, that I equate brainteasers with jogging bottoms: fine at home, but completely inappropriate for a job interview. Fortunately, pioneering companies such as Microsoft, Google and Facebook, which for years were staunch proponents of brainteasers, have not only turned away from them, but are now steadfastly against them.


Instead, important character traits of the applicants are now tested much more effectively using behavioural and situational questions. Behavioural questions provide an interviewer with insights into how you have dealt with specific, role-related challenges in the past. So, if your future manager wants to put your teamwork skills to the test, they may ask you to recount a situation where you successfully worked with someone with a very different personality to yourself.


With a situational question, you are confronted with a situation that you might find in the role you are applying for. Your interviewer is interested in finding out how you would deal with it. If we once again assume that your ability to work in a team is the skill being put to the test, you will, for example, come across the question of how you would deal with colleagues whose understanding of quality is significantly different to yours.


You can prepare well for both questions. Namely, by reading through the requirements for the position and thinking about where you have already successfully demonstrated the skills they are looking for (behavioural) or which situations in the future role might require these skills (situational). Reflecting on these questions in the days before the interview is an excellent way to prepare, whether that’s before falling asleep, taking a shower or going for a long walk. What works best for me personally is saying the question and answer out loud a few times, similarly to how I would practise for an important presentation at home. And anyone who has done this before may know how much more confident and self-assured you then are when it really matters.


And don’t worry; if you are still confronted with a brainteaser, then take the time to analyse the question in detail, ask questions if necessary and do not forget: the correct answer often has little relevance; it is how you get there that matters.


For the sake of completeness, however, here’s the solution to the brainteaser posed at the beginning. To start with, not only can you see if a light has been switched on, you can also feel it from the heat emitted when switched on. If we take advantage of this knowledge, the problem is now quite easy to solve. You flip the first switch and wait a few minutes. Then you switch off the first switch and flip the second. If you now go up into the attic, the bulb will either be switched off but warm (switch 1), be illuminated (switch 2) or not illuminated and cold (switch 3). It was easy, wasn’t it? Take this as a warm-up for your next interview!

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Marcel Hofstetter

Talent Sourcing & Relationship Manager

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