Are brainteasers still popular?
I've read that a bunch of the EB's that I hope to interview with tend to ask some brainteasers during interviews. However, most of the brainteaser threads on WSO are from 2009-2013ish and they don't seem to pop up too much nowadays, especially at larger banks.
Do you think I should still prep/worry about them, especially for EB's?
Has anyone had any recent experience with those types of questions?
Any general advice/ strategies / approaches on how to go about solving them during an interview?
100%, at EBs especially. Did a superday at Centerview Partners last year, and 2 out of 5 of the 30-minute interviews were brainteasers/weird fit questions. Things like: estimate how many bricks are on your college campus, what song best describes your work style, name 10 uses of a pencil besides writing. All interviewers were given a sheet with a pool of pre-approved questions that they chose from. They change every recruiting season.
Look through the WSO company database as well as Glassdoor. Some of these questions you can't really prepare for, but having a fun and positive attitude and not looking nervous as fuck really does help, I think.
Can confirm, at least for Centerview, as one of my friends went through a superday with them and he got pretty much the exact same questions that you listed in your post.
Haha had the exact same questions for my CV superday
What was your answer for 10 uses of a pencil besides writing?
What are they looking for from a song that best describes your work style? "Till I Collapse" by Eminem?
There are a ton of potential answers for the pencil use question. They are just trying to see how creative you can be with a pencil.
The song question deals with your ability to think on the spot. Usually giving the title of a song that makes sense with a work style (hopefully not negative) is fine.
been a while but...
fishing, chopsticks, darts, skewers, hair tie (for girls), firewood, and etc. yeah i realize some are pretty out there but they seemed to like the weird ideas lol
I was literally listening to that song while reading your comment haha
At a recent interview I was given a bunch of popular ones, but was also asked what rounded x would most closely yield a million in 2^x. Never heard that one before.
Yes - they are still popular, at least at London BBs.
This is just a logarithm...
Care to walk us through how you got that logarithm in your head...?
How to actually solve: you know 2^10 is 1,024 (or at least you know some power of 2 is 1,024, or at least you can double 2 in your head until you get close to 1,000...), so 2^20 is a little more than a million.
It is really going to depend on the interviewer and to be honest the universe of questions is so vast that I wouldn't spend a ton of your prep time going over these. At least have a general sense of how you would answer a few of the ones mentioned above. Otherwise focus on technical questions, your story, your rationale for joining that X bank, knowing the details of an M&A deal or two, having a stock or two that you follow/could pitch.
What I would also prepare for is mental math questions which I've gotten a number of at EB's especially. Something like 23x23 in your head is going to throw most people off if you're not ready, but is actually pretty doable if you break it down:
3x3 = 9 20x3 = 60 20x3 = 60 20x20 = 400
9+60+60+400 = 529
Also know your fractions: 1/2 = .50 1/3 = .33 1/4 = .25 1/5 = .20 1/6 = .16 etc.
A very popular question is something like, imagine a company is buying another company with a P/E of 14.0 - what is the cost of debt that would lead to an accretive deal?
First clarify if that is after-tax cost of debt (they say yes) and basically it is the inverse of 1/14. You know 1/7 is ~0.14, so 1/14 is approximately 0.07 so the cost of debt would have to be less than 7%
First off, I think you meant the inverse of 14, rather than the inverse of 1/14.
Also, were you referring to how the inverse of P/E is technically the cost of equity and since cost of equity is higher than after-tax cost of debt, then after-tax cost of debt must be lower than 7%?
Would've never figured this out in an interview -- didn't know 1/ (P/E) = return on equity until now, and I know it makes logical sense, but I'd prob freeze in an interview... so stressed now How common is it for them to ask finance-based brainteasers? By asking that q for example, they're automatically assuming that you're pretty familiar with cost of equity / P/E ratios / typical financing terms, etc. so there are so many layers to this q... Also, if I get a similar q in an interview, and have no clue what to say, any strategy you'd recommend? I feel like even if it turns out to be an easy one, I might just assume that I don't know the financial concepts behind it, and give up?
You're right, good catch.
Yes that is essentially the concept. You can prove it out with an example that shows the net income from the acquisition > net income reduction from the interest expense (don't have to worry about shares issued since it is purchased with debt).
Target Net Income: 10 Target P/E: 14.0 Implied Martket Cap: 14.0*10 = 140
Debt issued to fund transaction = 140 Inverse of 14.0 = ~.07 Interest Expense = 140*.07 = 9.8, which is approximately the 10 of Net Income contribution from the target hence the breakeven point
Damn you break down mental math that far?
I've always tended to just round one of the numbers to the nearest 10. So 23x23 would be:
23 x 20 = 460 23 x 3 = 69 460 + 69 = 529.
Props to you though, I feel like I could get lost doing it your way if the digits were any larger.
Edit: Apparently Asterisks don't work.
I think the extent to which you would break down the mental math depends on how comfortable you are with multiplying numbers. Some people might struggle with multiplying 23 and 20 in their heads so they have to break it down further.
Was about to ask this same question. I need to get better at the estimation questions but I've read some of the approaches to these. Some notable ones I've seen:
How many golf balls fit in a Boeing 747? How many square feet of pizza was eaten in the US last year? Estimate the size of the tie market.
I was watching some Victor Cheng and he said to practice these it's best to try and ask the same questions when you come across random objects during your average day.
For example, when you buy a coffee maybe ask yourself how many pounds of coffee beans Starbucks buys each year. Just going through the process is good practice. The interviewers just want to see your thought process I guess. Quaneaser also shared some good points about mental math.
I love one brain teaser:
A bat and a baseball cost $1.10. The bat costs one dollar more than the baseball. How much does the baseball cost?
Tons of Ivy league kids who are nervous mess this up; it's a good way to show who can think clearly and confidently under pressure.
Source: https://www.amazon.com/Thinking-Fast-Slow-Daniel-Kahneman/dp/0374275637…
$0.05?
Yes
I bet you're right. Most people would probably say the baseball costs 10 cents and they figure the bat is $1 but that would equal $1.20 total.
Baseball: $0.05 Bat: $1.05 Total: $1.10
This is good shit we need a thread just for brainteasers if we don't have one already.
I like this type of brainteaser a lot too because it's not really testing your logic as much as it's testing your ability to understand that things aren't always as simple as they may seem. For example, the first time I heard this, I came up with the most common wrong answer in my head, but then I also considered why I would be asked such an easy question (and that there must be some sort of trick to it). This led me to think through it more carefully such that I ended up getting to the right answer on my first try.
People nowadays want stripteases more than brainteas(e)(er)s.
Yep, got asked some in Nov-December at American IBs in London...
Got two yesterday for an American BB: 1. how much is the angle create on the clock by the clock hands at 3.15? 2. you have 9 identical balls, 8 have the same weight and one is heavier than the others - you have only two weighings, how do you figure out which of the balls is the heaviest one? nothing too complex
Thanks for that! And wow you had a super day with a BB yesterday? PatrickBateman1
Apologises, I forgot to mention it is for an OC in Europe!
Guys lets post some more teasers and then your answer to them in separate posts.
...
I just think it's interesting to see peoples' thoughts and compare. I also don't want to go and give people answers to them for interviews though.. double edge sword here.
I wish I could find it again (and maybe someone will and post it here) but there was a youtube video that had like 5 brainteasers and it was really popular. So popular, that I've had those pop up in interviews from companies that think they're being clever but, come on, you're asking questions from youtube!
The one I remember - and I've actually been asked in interviews - was about WW II airplanes and studying the bullet holes. Due to supply shortages, you can only fortify a portion of the airplane. Which part of the plane do you choose to fortify to increase the survival rate of your pilots?
Wow, such a weird question, thanks for sharing. I'll definitely search for the video. What was the answer to that q, I'm super curious now
Ah, found it here -- https://www.braingle.com/brainteasers/teaser.php?op=2&id=18194&comm=0
Thanks for posting that. The video was slightly different. In the video, the answer was the gas tanks. You want to say wings, but its the gas tank. The rationale being that bullet holes were not uncommon. So survival wasn't about avoiding bullet holes, it was about your ability to get back to base for repairs. You can fly with holes in your wings but you can't fly with holes in your gas tank.
A butcher stands 5'10" tall and wears size 13 shoe. What does he weigh?
Meat lol
Damn. Too easy I guess lol
A good one I got in an economic consulting interview back in the day:
There are 100 lightbulbs, each with an on-off switch (assume all start in the off position)
There are 100 people and each takes their turn flicking the switch on certain lightbulbs. The first person goes through and flicks the switch on the 1st, 2nd, 3rd, 4th, etc. lightbulb all the way up to 100.
The second person goes in and flicks the switch on the 2nd, 4th, 6th, etc.
The third person goes in and flicks the 3rd, 6th, 9th, etc.
This continues until the 100th person flicks just the 100th switch
Two questions, after all 100 people have gone:
1) Is the 68th lightbulb on or off? 2) How many of the 100 lightbulbs are in the on position?
SB because I had to look it up. Good one
Brain Teasers with Definitive Answers
What is the angle between the hands on the clock if the time is 3:15?
You have a block of cheese painted all red only on the outside. If you cut the block into 10 by 10 squares, how many squares will have red paint on any portion?
You have 12 black socks and 18 white socks in a drawer. The power goes out in your house and you can't see anything. How many socks do you need to pull out of the drawer to make sure that you have at least one matching pair of either color?
You have a 5 gallon bucket and a 3 gallon bucket. You need to make a container with exactly 4 gallons of water in it, how is this possible?
What is 23^2?
What is 17*23?
A driver is going to drive 100 miles. If they drive the first 50 miles at 50 miles per hour, how fast do they have to drive the second to average 100 miles per hour for the entire run?
A stock is trading at 10 and 1/16. There are 1 million shares outstanding. What is the stock’s Market Cap?
You are the owner of a large mid-evil farm and your peasants demand that they are paid every day in bars of gold. You have a measuring device that allows you to cut the bar of gold in exactly the length that you please. Your peasants work 7 days a week. You can only cut the gold bar twice. How can you pay your peasants?
Three missionaries and three cannibals want to get to the other side of a river. There is a small boat, which can fit only two. To prevent a tragedy, there can never be more cannibals than missionaries together. How is this possible?
There are three switches downstairs. Each corresponds to one of the three light bulbs in the attic. You can turn the switches on and off and leave them in any position. How would you identify which switch corresponds to which light bulb, if you are only allowed one trip upstairs?
A Petri dish hosts a healthy colony of bacteria. Once a minute every bacterium divides into two. The colony was founded by a single cell at noon. At exactly 12:43 (43 minutes later) the Petri dish was half full. At what time will the dish be full?
There are ten apples in one basket and ten people in a room. Can you distribute the apples so that each person received one and there is one apple left in the basket? A professional fisherman caught 30 fish during a 5-day tournament. Each day, he caught three more fish than the day before. How many fish did the fisherman catch on the first day?
Find the four-digit number in which the first digit is one fourth of the last digit, the second digit is 6 times the first digit, and the third digit is the second digit plus 3?
A man wanted to enter an exclusive club but did not know the password that was required. He waited by the door and listened. A club member knocked on the door and the doorman said, "Twelve." The member replied, "Six" and was let in. A second member came to the door and the doorman said, "Six." The member replied, "Three" and was let in. The man thought he had heard enough and walked up to the door. The doorman said, “Ten" and the man replied, "five." But he was not let in. What should have he said?
Does the Catholic Church allow a man to marry his widow's sister?
Brain Teasers without Definitive Answers (5) How tall is the Empire State Building in terms of quarters stacked on their sides?
How many ping-pong balls fit into a 787 Dreamliner?
What is the annual snowfall over the United States in inches?
One stock is trading at $8 and another is trading at $34, which one has the higher growth potential?
How do you explain the sky to a blind person?
WSO could work on these together. I don't have all the answers... Good luck and have fun!
“a large mid-evil farm”
mid-evil??? I don’t think that’s an autocorrect mishap. It’s a test within a test.
Could be. Those have been shared quite a few times through the grapevine so someone might have messed up a copy paste / misspelled it.
This wasn't given to me as a "you'll be given these questions as a test" but in more of a "these are the types of questions you may run into" context. I would think small discrepancies would be sprinkled throughout a bit more frequently if it really was testing for attention to detail.
I did make some good friends trying to solve them all as a newbie freshman years ago. Hopefully the problems can do that for someone else.
Regardless, it is an honor to have DickFuld respond.
Yes, at least in London. At interviews with BB's I've been asked about the distante between X and Y country and what's the square root of 0.9, among others.
When are motor vehicles owned by a company not recorded under PP&E on the company's balance sheet? BDWK
Is this a trick question? lol. If the motor vehicle is used to help generate revenue for the company then it should be recorded under PP&E.
Haha yeah it's somewhat of a trick q, I thought it was really cool
The answer: Ford, Tesla, and other car companies will record it under Inventory.
Recall that Inventory is part of Current Assets, while PP&E is a Long-term Asset.
Not to be boring lol, but could an answer just be that it could be considered an operating lease (if it doesn't meet the 4 capitalization requirements)?
An operating lease wouldn't be included on the balance sheet (so you're right in that aspect) but since it's a lease it wouldn't be considered ownership so I'm not sure that answer would meet the criteria the question requires.
You're an accounting major aren't you lol
Most of the stuff mentioned in this thread is such nonsense. Nothing to do with performing the job well, and just a lazy way for interviewers to weed out a mass of kids
The only potentially relevant ones are off the wall stuff that shows what kind of person someone is and how they can present themselves (song to describe work style) or questions actually relevant to the job (which company has more growth potential)
10 other uses for a pencil? I can only think of one... stabbing myself in the eye with it so I can escape from such a bizarre waste of time
Agree that a lot of them are laughable. Very hard to prepare for those odd-ass questions so it's just a way for interviewers to induce pressure and see how you react. Maybe they're even looking for a little creativity in your answer? As the interviewee, it's hard to take some of them seriously, though. "You're shrunk down to the size of a pencil and put in a blender, how do you get out?"
WTF? It would be pretty difficult to answer that question with a straight face.
Honestly if someone asked me that now in an interview, I’d just walk out. Wouldn’t want to work for someone that thinks that is an effective way to conduct an interview. Granted I’m past the point where I’d be applying for an entry level job, but such a question provides no relevant information
Curious as to the response timing. On some of the more challenging ones, is it acceptable to write down a couple of notes prior to responding? Or would this potentially ding you as it shows you need more time for these concepts
The reason why these are asked is to (supposedly) see how you think and work through a question. They should mark you as "correct" if you come up with a reasonable rationale, regardless of whether your answer is correct. So you should definitely feel free to take your time and write down items to show the interviewer. When I do these, I usually talk out loud so that they can hear my reasoning and I have found that most interviewers respond favorably to that.
I really appreciate this. I am far from Einstein, and tend to rush through questions sometimes, focusing on speed over quality. Thank you, +1
I had two brainteasers for an American BB in London.
They were fairly basic though, I found them online beforehand.
1) A lilypad doubles in size each minute. In one hour they will cover the entire pond. How full is the pond after 58 minutes?
2) Two guys are running a marathon. They were born in the same hospital, on the same year, on the same day and have the same mother and father. However, they are not twins. What are they?
I cant believe #1 is still around. That question & similar variants have been around since the beginning of time and most people know the way to work the answer(s).
Having said that, its a good barometer. If you are interviewing (or about to interview) and you don't know the answer to #1 then you should really do more work on the brain teaser side of your interview skills.
There are definitely some brainteasers that are still pretty common in banking interviews. For example, I have also been asked the lilypad question in an IB interview.
I believe the WSO guide has a section with the most common brainteasers. I recommend memorizing the answers to those brainteasers as they continue to be asked every year. Maybe memorizing the logic behind those brainteasers can help in figuring out a brainteaser you have never heard before.
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