Some places do ask “puzzle questions” - but they aren’t generally for testing IQ, they are intended to allow the interviewers to see how the candidate approaches a problem. We don’t say: “Here is a problem, figure out the answer” - we say “Here is a problem, we don’t care whether you get it right or not - but just tell us how you’re trying to solve it.”
There are many examples - we used:
You’re playing ‘Russian roulette’ where you have a loaded revolver, and take turns with another person putting it to your head and pulling the trigger. This time, there are two bullets, placed in consecutive chambers of a 6 shot revolver. The other person spins the cylinder, puts it to their head and pulls the trigger…CLICK!…nothing happens. They hand the gun to you - you have the choice to either spin the cylinder again or to leave it as-is before putting the gun to your own head and pulling the trigger. Which is the safest thing to do?
If you just tell us the answer - that’s not what we wanted - so we’ll just grab another question and give you that instead.
We want you to be doodling on the white board - or doing statistics with math - or…whatever it is you do to figure it out.
Worst thing you can do is to guess…”It doesn’t matter”…is a typical guess and that would be a black-mark on the interview form!
I like reactions like “Well, if I spin again, I have no information about the outcome - but if I don’t spin again, then I must know something I didn’t know before the last guy pulled the trigger”…which is good. Then we can ask “So…what use is that information?”…and so forth.