I had an interview for a major investment bank for risk internship role last week. The interviewer asked me a brainteaser, which is pretty appropriate question. But I never expected them to ask a brainteaser and therefore did not prepare. I spent about 5 minutes, still coudn’t get it, so she gave me the answer. At least I gave her my logical steps though.
Am I f****d up?
Ur ok - u gave ur logical steps. They’re not expecting u to know everything, they just want to know you have ideas and logic and the ability to learn.
What was the brain teaser?.. Dnt give us the answer
I hate brain teasers but don’t stress over it. Remember your resume gets you the interview and your experience & personality get you the job.
How do you prepare for brainteaser? Do all the brainteasers you can prior to the interview?
Not being able to solve it is often not a problem. What they want is to see how your mind attempts to wrap around difficult problems. If the answer is important, they will often give you hints to get there if you are struggling, though they may give you a hint just to get you started even if the answer is unimportant.
As long as your approach was reasonable or interesting, you are likely ok, even if you didn’t fully solve it or needed some hints.
I messed up a simple problem in my very first financial interview. I did it right but was uncomfortable with the result because something didn’t feel right. The thing that didnt feel right was that I didn’t account for risk aversion, but the interviewer wasn’t actually asking me to account for it, so I would have done better by keeping my mouth shut rather than to write back and explain myself the next day.
Most of the time I interview pretty well, but there have been occasional moments where I cringe to remember myself.
The last time someone asked me a brainteaser, I was so mad I almost walked out. At some point people move beyond that. Maybe for entry level when it is not possible to talk about business.
If a chicken-and-a-half laid an egg-and-a-half in a day-and-a-half, how much would a pound of butter weigh?
#aPound
Sometimes it depends on the firm’s culture. I had one of those long 8-people-in-a-day interviews at Alliance/Bernstein one time and absolutely every last person gave me a brain teaser (they varied quite a lot in difficulty). I never bothered to ask, but I have a feeling that it’s simply part of the culture that every interview for someone in an analytical role is expected to include some kind of brain teaser.
The same as a pound of lard. 
I had an interview a few years back and got asked a brainteaser midway through the interview, I got about 3/4 through it and then just couldn’t come up with a logical estimate to get myself to a reasonable answer.
I spent a long time after the interview kicking myself about not getting it, years later I bumped into an old colleague and it turns out he was now working for the company that I’d been rejected by in the role I’d interviewed for. Over a beer I asked how he answered the question and he said his response at the time was “I don’t know, my brain isn’t wired like that”
I did so bad on 2-3 brain teasers in a row that they gave me some type of complicated cube volume calculation that I still couldn’t finish (last step was multiplying double digit numbers together and I can’t do that in my head). Interviewer wrote something and moved onto some other questions LOL! Still got an offer, which I ended up passing on for another. Like gringo_bob, my brain is not wired for those questions.
The point of the brain teaser isn’t to see whether you know the answer or not. It’s to see how you think, come to a conclusion, and support that conclusion with logic.
I’ve been through probably hundreds of interviews and don’t recall the answer ever being an issue. Its how you approach the question with logic. I’ve had “how many quarters would stack up to this building height” and “how many lightbulbs are in NYC” and the like. If you don’t know certain constraints, you can ask. At MS when asked the quarter stacking question, I said bluntly - I don’t know how many floors are in this building. Correct me if i’m wrong, but I estimate 50. The interviewer gave me the exact number of floors, I estimated the floor height in feet, inches, how many inches, and how many quarters per inch. Sometimes I didn’t even do the math. I said the answer is X times Y. Just do the most you can and your approach is more important than sheer math.