Interview brainteasers are a topic that I personally love to hate…
On the one hand, I see the appeal. They’re certainly ‘fun’ and they do break the ice.
On the other hand, they have the ability to totally sabotage the entire interview process, putting candidates off and making them feel even more nervous.
However, at Response, we try not to let our personal biases get in the way of a good blog topic, so this week, I’ve been researching some interview brainteasers for you!
I’ve even added a little festive twist – it is Christmas, after all!
1. How many “Father Christmases” are there in the UK?
The internet is packed full of alternatives to this festive little gem, including…
- How many lampposts are there in the UK?
- How many potatoes (in kg) do McDonald’s in the UK sell in a year?
- How many golf balls would fit into Wimbledon?
… each assessing mental arithmetic, critical thinking, common sense, creativity and performance under pressure.
Let’s be honest, you’re not really looking for the right answer (you’ll be waiting a long time if you are)… you’re looking for someone who can make a sensible attempt at answering.
Look out for critical reasoning skills; how do they go about tackling the question?
They may come up with the most outrageously wrong answer ever, but if they walk you through their calculations, based on sensible presumptions, then it’s a great sign.
Hasty and un-thoughtful answers show that they’re not taking the process seriously or they don’t really understand what you’re asking from them (IE, a well thought-out answer).
Watch out for candidates who visibly seem frustrated and refuse to play the game!
2. As a Christmas gift…
…parents buy 16 computer games for their 3 children (that’s just asking for trouble)! The youngest gets 1/8 of the games, the middle child gets 1/4 of the games and the oldest gets 1/2 of the games (seems fair…)
How many games does each child receive and how many do the parents keep?” Courtesy of Julie Turnbull.
If mathematical skills are important to you then this percentages-based brainteaser is a great way to test your candidates and there is, of course, a correct answer (scroll down to find out).
Anyone who manages to keep their cool and answer this question correctly can clearly hold it together under pressure (the maths bit isn’t that difficult)!
If a candidate gets close, but perhaps make a silly mistake while they’re calculating, don’t be too harsh! Under strict interview conditions, it can be difficult to focus!
Ask your candidate to talk you through their sums as they go along. You’ll soon suss it out if they can’t do basic maths.
Again, hasty, un-thoughtful answers show an unattractive laziness and disregard for the interview.
You have 1/8, 1/4 and 1/2. If you give them a common denominator of 16 then you end up with 2/16, 4/16 and 8/16 and so the answer is…
Youngest Child: 2 games.
Middle Child: 4 games.
Oldest Child: 8 games
Parents: 2 games
3. 2 mums & 2 daughters went out for Xmas dinner…
…each ate one portion, yet only three portions were eaten in total. How is this possible?
Have you got it? Scroll down to find out!
If a candidate is listening and focusing on the question, it’s actually quite a simple brainteaser for anyone with a critical thinking, common-sensical brain behind those eyes.
Unfortunately, any other answer is just plain wrong!
Candidates who give up may have let their nerves get the better of them…
Of course, they may just not be as critically minded as others. You’ll have to use your intuition!
If you do have a particularly nervy candidate who struggles with brainteasers (and you’re still dead set on asking them…) you can always make things easier for them!
Perhaps you could repeat and reword the questions and give them a couple of hints?
It was a grandma, mum and daughter.
4. Which of these letters is the odd one out?
OK – so this one’s not that Christmassy – but it’s still a brilliant brainteaser (I just couldn’t leave it out).
“A F H K L N Y Z”
It is pretty difficult though and you may have to give your candidates some time and/or a couple of hints before they get it.
Scroll down to discover the answer!
Anyone who gets the right answer is a winner in my book.
It shows really quick critical thinking, a keen ability to notice patterns and of course, performance under pressure.
It would be far to harsh to write someone off because they couldn’t answer this question, especially under the added pressure of you watching over them.
However, slap-dash, lazy answers and visible signs of frustration could be personality warning signs for the future.
L – because the shapes of the other letters are all made up of three lines each.
5. You have a 3-Litre jug…
Do you recognise this little riddle?
…a 5-Litre jug, and an unlimited supply of mulled wine. How do you get exactly 4 Litres of mulled wine without estimating?” UBS Investment Bank
I simply couldn’t do a Christmas blog on brainteasers, without including this little riddle from Die Hard With a Vengeance (a Christmas-film favourite of course).
It takes some thinking to work out the answer to this question – again some candidates may need paper and a pen – but it is certainly doable. Just ask McClane!
Still, it’s certainly impressive if they do get it right.
These types of questions are likely to frustrate some interviewees so watch out for those who aren’t willing to play the game. It’s an interview after all and you make the rules.
Also be wary of candidates who answer this question a little too quickly – they’ve blatantly heard it before!
Click here to find out from McClane himself!
A quick heads-up…
It’s really important that you don’t base your entire interview on brainteasers like these.
They may go down well with some of your more confident candidates, but are likely to put others off – remember, recruitment is a two-way street!
If you MUST, then perhaps throw one (or at most two) into the process, to catch them out, when an interview is going particularly well and/or seems too rehearsed.
Above all else, try not to be too hard on your candidates – it’s important to put them at ease if you want to see the ‘real them.’
Remember, they’ll be judging you just as readily as you are judging them…