Interview Brain Teasers

[Hank Scorpio]

I know there was a big post on this in the past, but is there anything you can do for an upcoming interview to prepare for brain teasers? I've never been good at them; is looking over the popular ones and memorizing them my best option?

Here is the site I have:

http://www.techinterview.org/archive/index.html

[AvivaSimplex]

Cool link. Practicing can definitely help. Go through as many as you can find. Don't just try to memorize the answers, try to solve them. There is a certain type of lateral thinking in most brainteasers, and practice can improve it. Plus by processing them deeply, you'll memorize them without trying.

[seanw]

On a related note: what do you do when the interviewer asks a brainteaser you already know?

[Misfire]

WTF kind of interview uses these?

[rsk111]

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On a related note: what do you do when the interviewer asks a brainteaser you already know?

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This is the best case scenario. Just pretend you've never heard it and start reasoning it out. Go slow and explore some avenues you know to be wrong, but explain why ( If it's really hard, and you get it too quickly, then they'll assume you heard it before). On the other hand, if you try to fake it too much, the interviewer might try to give you helpful hints, and obviously you don't want these. So it's a fine balance.

[Hobbs.]

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WTF kind of interview uses these?

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finance

[ChipStorm]

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WTF kind of interview uses these?

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finance

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I use questions like these all the time when I interview candidates, which is most every week. My group at work is hybrid finance/quant/programming.

* Practicing absolutely helps. OP, you should do more than look them over, you should try to work them out.

* If an interviewer asks one you know, you tell him/her you've seen it, or you are a complete scumbag and deserve to be fired. You would also be stupid not to tell, since you get points for being interested enough in puzzles to already know one.

* These are asked for a couple of very good reasons. First, a person's ability to solve them is (very) loosely indicative of good general problem-solving ability, which in my case is what the job is about.

Second and just as importantly, a candidate's interest in engaging in such puzzles is a good indicator of attitude: desire to take on a challenge, to work something out interactively, on the fly, with a colleague. Even candidates who never get the right answer can do very well, with the right attitude.

[Butso]

[ QUOTE ]
[ QUOTE ]
On a related note: what do you do when the interviewer asks a brainteaser you already know?

[/ QUOTE ]

This is the best case scenario. Just pretend you've never heard it and start reasoning it out. Go slow and explore some avenues you know to be wrong, but explain why ( If it's really hard, and you get it too quickly, then they'll assume you heard it before). On the other hand, if you try to fake it too much, the interviewer might try to give you helpful hints, and obviously you don't want these. So it's a fine balance.

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Don't do this. Its harder than you think to do it convincingly

[rsk111]

[ QUOTE ]
[ QUOTE ]
[ QUOTE ]
On a related note: what do you do when the interviewer asks a brainteaser you already know?

[/ QUOTE ]

This is the best case scenario. Just pretend you've never heard it and start reasoning it out. Go slow and explore some avenues you know to be wrong, but explain why ( If it's really hard, and you get it too quickly, then they'll assume you heard it before). On the other hand, if you try to fake it too much, the interviewer might try to give you helpful hints, and obviously you don't want these. So it's a fine balance.

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Don't do this. Its harder than you think to do it convincingly

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I agree it's harder than you think. I just consider that part of interview prep. Also I never suggested lying if they ask you if you've heard it. But if they ask you to solve it, then solve it.

[Taciturn]

I think it's generally a good idea to tell the interviewer if you have heard the brain-teaser before. I have been in that spot and the interviewer acted very pleased that I would be honest enough to state this.

(Though, I could understand playing along and acting as if you haven't heard them before if that is the only way you would get them right... The really unethical might even lie about hearing a brain-teaser before when they think that they'll be unable to answer it).

Here's a couple of common ones:

There are nine diamonds, all look exactly alike, but one weighs slightly more than the other eight. You have a balance that you can use only two times. How do you determine which diamond weighs slightly more?

And:

When a clock reads 9:40 what is the angle between the hour and minute hands? (time I chose here is random, I doubt it matters).