When it comes to assessing candidates, asking the right questions in an interview is vital.
But what about technical or thinking-based roles?
Well, logic-based interview puzzles are fast becoming one of the most popular ways to help employers and recruiters unearth the brightest candidates.
And not to mention it’s a prime example of how to get an insight into their thought processes too.
The benefits of asking brain teaser questions
In particular, brain teaser interview questions challenge the logic of candidates and test their ability to react well in the event of a pressured situation – which are both attributes required in tech, IT and various other industries.
Big corporations like Google, Facebook and Airbnb are early adopters of this method, believing that these challenging questions give them the edge over their competitors.
Integrating logic based interview questions like brain teasers isn’t necessarily about testing a candidate’s ability to get the right answer, but to measure to see how they apply logic and question the information offered.
While competency-based interviews are still extremely important, throwing a few curveballs in the mix will make your company stand out from others.
It also focuses on the present instead of always drumming on about a candidate’s past achievements.
With this in mind, here are five very tricky brain teasers for you to use in your next interview.
(5 points if you can get one of the answers right without cheating.)
Question 1
You have a 3 gallon jug and 5 gallon jug, how can you measure out exactly 4 gallons?
Answer
Firstly, the candidate should state that they can’t get the final amount in the 3 gallon jug as it’ll overflow, so they’ll have to focus on the 5 gallons one.
Next, they must fill the 3 gallon jug and pour it into the 5 gallons one.
Fill the 3 gallon jug again and pour it into the 5 gallons one until it reaches the top – which should leave 1 gallon in the 3 gallon jug.
They should then empty the 5 gallon jug and pour the remaining 1 gallon from the 3 gallon jug into the now empty 5 gallon one.
Finally, fill up the 3 gallon jug and pour it into the 5 gallons one (with 1 gallon already in it), and hey presto, you have 4 gallons!
Question 2
How many golf balls can you fit into a school bus?
Answer
This question is particularly good for testing logic, as there isn’t really a right answer without testing it.
A smart candidate will think carefully about the question and consider other factors like how big the bus is and is it empty.
If a candidate doesn’t try very hard to answer this, then it’s not a good sign.
Question 3
Why are manhole covers round?
Answer
Once again, this question tests logic.
Plus, it’ll give you and the candidate a nice welcome break from math questions too!
The candidate should point out that a circle is the only shape that cannot fall through itself.
So in this example, the manhole cover can’t accidentally fall down the hole and put pedestrians’ lives at risk.
You may be interested to know that this question is being used by Microsoft and Google!
Question 4
Describe the internet to someone who has just woken up from a 30-year coma.
Answer
In theory, there isn’t a wrong way of answering this.
Instead, it’s testing a candidate’s ability to concisely sum up a major technological advancement.
This is a attribute to have when it comes to doing pitches, selling products and so on.
This interview question can also act as a nice icebreaker too as it can throw up some funny responses.
Question 5
You are kidnapped by a Russian gangster.
He puts two bullets in consecutive order in an empty six-round revolver, spins it and points it at your head.
He pulls the trigger once, but you’re still alive.
The Russian gangster then asks you, “do you want me to spin it again and fire or pull the trigger again right away?”
Answer
This brain teaser interview question is all about working out the probability.
The key hint here is the fact that both bullets were loaded in consecutive order and the first shot was a blank.
The possible scenarios are:
- XBBXXX
- XXBBXX
- XXXBBX
- XXXXBB
The other two scenarios were wiped out after he pulled the trigger immediately – BBXXXX and BXXXXB.
If you look at the four scenarios, there is only a 25% chance that the next shot would fire a bullet (the first one).
However, if you decide to re-spin, there are two bullets left and six total slots, giving you a 33% chance of getting shot.
Summary
Got a headache? Me too!
As I previously mentioned, these brain teaser interview questions are about testing logic, questioning the information provided and working well under pressure.
So don’t discard a candidate if they aren’t able to find the right answer.
If you do this, it could be a long, long recruitment process.
Enjoyed reading this? Then you might find some of these other interview question blogs useful:
- ’11 Interview Questions That Will Reveal The Real Truth About Your Candidates’ – read
- ‘5 Pointless Interview Questions, We Should All Stop Asking Candidates’ – read
- ‘8 Interview Questions to Lighten the Mood’ – read
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