General Principlesknowledge if you are unprepared.Although a complete review of quant interviewproblems is impossible and unnecessary,practice does improve your interview skills.Chapter 2 Brain TeasersFurthermore.many of the behavioral.technical and resume-related questions can beanticipated.So prepare yourself for potential questions long before you enter anIn this chapter,we cover problems that only require common sense,logic,reasoning,andbasic-no more than high school level-math knowledge to solveIn a sense,they arereal brain teasers as opposed to mathematical problems in disguise.Although these brainteasers do not requirespecific math knowledge,they are no less difficult than other3.Listen carefullyquantitative interview problems.Some of these problems test your analytical and generalYou should be an active listener in interviews so that you understand the problems wellproblem-solving skills;some require you to think out of the box;while others ask you tosolve the problems using fundamental math techniques in a creative way.In this chapter,we review some interview problems to explain the general themes of brain teasers thatthe key words to help you remember all the information.For complex problemsyou are likely to encounter in quantitative interviews.interviewers often give away some clues when they explain the problem.Even theassumptions they give may include some information as to how to approach the problem.So listen carefully and make sure you get the necessary information2.1 Problem SimplificationIf the original problem is so complex that you cannot come up with an immediate4.Speak your mindsolution,try to identify a simplified version of the problem and start with it.Usually youWhen you analyze a problem and explore different ways to solve it,never do it silently.can start with the simplest sub-problem and gradually increase the complexity.You doClearly demonstrate your analysis and write down the important steps involved ifnot need to have a defined plan at the beginning.Just try to solve the simplest cases andnecessary.This conveys your intelligence to the interviewer and shows that you areanalyze your reasoning.More often than not,you will find a pattern that will guide youmethodical and thorough.In case that you go astray,the interaction will also give yourthrough the whole problem.interviewer the opportunity to correct the course and provide you with some hints.Speaking your mind does not mean explaining every tiny detail.If some conclusions areScrewy piratesobvious to you,simply state the conclusion without the trivial details.More often thannot.the mterviewer uses a problem to test a specific concept/approach.You should focusFive pirates looted a chest full of 100 gold coins.Being a bunch of democratic pirates.on demonstrating your understanding of the key concept/approach instead of dwellingthey agree on the following method to divide the loot:on less relevant details.The most senior pirate will propose a distribution of the coins.All pirates,inc/uding themost senior pirare.will then vote.If at least 50%of the pirates (3 pirates in this case)5.Make reasonable assumptionsaccept the proposal,the gold is divided as proposed.If not.the most senior pirate will beIn real job settings,you are unlikely to have all the necessary information or data you'dfed to shark and the process starts over with the next most senior pirate...The process isprefer to have before you build a model and make a decision.repeated until a plan is approved.You can assume that all pirates are perfectly rationald.Finally.beingIn interviewsintervicwers may not give you all the necessary assumptions either.So it is up to you tothey want to stay alive first and to get as much gold as possible seconmake reasonable assumptions.The keyword hereblood-thirsty pirates,they want to have fewer pirates on the boat if given a choiceassumptions to the interviewer so that you will get:is reasonable.Explain yourbetween otherwise cqual outcomesimmediate feedback.To solvequantitative problems it is crucial that you can quickly make reasonable assumptionsHow will the gold coins be divided in the end?and design appropriate frameworks to solve problems based on the assumptions.Solurion:If you have not studied game theory or dynamic programming,this strategyWe are now ready to review basic concepis in quantitative finance subject areas andproblem may appear to be daunting.If the problem with 5 pirates seemscomplex.wehave fun solving real-world interview problems!can always stari with a simplified version of the problem by reducing the number ofpirates.Since the solution to I-pirate case is trivial.let's start with 2 pirates.The senior2