Struggling with brain teasers

trazer985:

No problem is as easy as it looks, none is as hard as it seems.

Every problem has an answer, so work on the basis that it must be doable.

You aren't expected to get it right instantly. If you do, you've seen it before and you MUST say you have, if you have. (Something like, sorry I'm familiar with this one).

Don't answer quickly, never be 100% in your response (most will ask you how sure you are of your answer).

In the case of identifying something (which marble is lighter etc.) you're looking for a unique identifier, or way of labelling each option individually.

For deduction (the pirate problem) simplify the variables (do it with 1 pirate, then 2 pirates).

For logical principles, take it to extremes, does the number of faces on the dice affect hte probability? (not always). Try it with a 2 sided dice and a million sided dice.

There is never superfluous information. Everything given is very specific and exact. Why 5 days? What can they do on the 5th day that they couldnt do on the 4th?

That's about it, I trained myself up pretty well on these, can post a few if you want.

That would be a great help, thanks.

Are we able to use pen and paper, or will all calculations have to be done in your head. Also, should we talk it through with the interviewer as we go or think it through in our heads first?

Thanks

This. start with the basics and invest in some good books to practice. There is a lot of material available online as well that you can use as a starting point.

couchy:

Practice makes perfect. Brain teaser are tough to cram so strt early. WOould recommend taking a basic math problem solving class.

BTbanker:

What is the angle between the hands on a clock when the time reads 3:15?

.1309

I'm sure it's not as simple as "either you have it or you don't". Brainteasers are supposed to put you off balance to illustrate to the interviewer how you handle pressure. Other than trying to memorize as many brainteasers out there, I would just suggest approaching the problem logically and trying to reason it out. I'm sure they do not expect you to nail each one perfectly, as long as you show an insightful thought process (Map it out).

Word!

I have completely bombed the brain teasers and still came away with an offer.

I personally think these teasers are a very strange way to evaluate a candidate.

On a somewhat related note --- I had a prop trading interview a while back and the guy starting asking me a series of mental math questions in the middle of the interview. I felt like I was in an SNL skit.

I have completely bombed the brain teasers and still came away with an offer.

I personally think these teasers are a very strange way to evaluate a candidate.

On a somewhat related note --- I had a prop trading interview a while back and the guy starting asking me a series of mental math questions in the middle of the interview. I felt like I was in an SNL skit.

it doesnt matter if you get the brain teaser right or wrong.... all they want to see is how you think... they want to see how you approach the problem... as long as you can walk them through with logical reasoning.... it should be fine..

it doesnt matter if you get the brain teaser right or wrong.... all they want to see is how you think... they want to see how you approach the problem... as long as you can walk them through with logical reasoning.... it should be fine..

Usually brainteasers require you to find the key trick, seeing the big picture while knowing all the details, and having been around the block.

They are tough to train because you can't just pick up a book and "get better" at them because each brainteaser is unique and has a different key insight.

I hate to give you this answer, but in the end, brain teasers are a test of maturity regarding the key insight it's testing. You can't prep for them besides having seen them before or knowing that particular topic very well. But most prop trading firms will know a few questions that candidates have never heard before.

Try to read up on all the popular ones. Pray to god if you get one you've never heard of during an interview..

you can train the way you think, and that in turn will teach you how to do brainteasers, as a by product of being a better thinker.

you can train to do them to an extent... by solving a large number, you get accustomed to seeing them and thinking in a particular way. you automatically search for some solutions/similarities which you remember from your previous exercises. but if you get a very new type of brainteaser that requires a new direction change in your thoughts - that is about being really smart. with limited time, it can be extremely hard.

for example, i remember threads on wso such as "monday brainteaser" or something like that... there were dozen of different threads. i could say by reading the responses that so called "smart guys" that are regular posters here are just the guys who are familiar with brainteasers in general. those guys also lacked a lot of creativity because all they did was trying to find similarity with old cases that they already knew. they loved to get credit for being "smart", but in reality, they are not even above average. they just prepared for it better or have gone through more suitable education.

ultimately, you will probably score well if you give it enough practice (at least it will help with confidence and structuring the problem to an extent), but some people might just have superior natural ability in solving those.

p.s. i would go as random as possible in practice; you can google millions of examples on the internet. you can also find pdf books around...

yes there are about 150 of them on the internet, memorize them all and you will look really smart. the ones giving them are usually dumbasses trying to feel important when giving an interview.