Brain Teaser 141d1i
This document was ed by and they confirmed that they have the permission to share it. If you are author or own the copyright of this book, please report to us by using this report form. Report 3i3n4
Overview 26281t
& View Brain Teaser as PDF for free.
More details 6y5l6z
- Words: 3,940
- Pages: 10
Investment banking interview brainteasers | IBankingFAQ
30/07/2017, 09*13
You have 100 balls (50 black balls and 50 white balls) and 2 buckets. How do you divide the balls into the two buckets so as to maximize the probability of selecting a black ball if 1 ball is chosen from 1 of the buckets at random? Just to be perfectly clear, you are assuming that one of the two buckets is chosen at random and then one of the balls from that bucket is chosen at random. You want to put 1 black ball in 1 of the buckets and all of the other 99 balls in the other bucket. This gives you just slightly less than a 75% change of having a black ball chosen. The math works as follows: There’s a 50% chance of selecting the bucket containing 1 ball with a 100% chance of selecting a black ball from that bucket. And a 50% chance of selecting the bucket containing 99 balls with a ~49.5% (49/99) chance of selecting a black ball from that bucket. Total probability of selecting a black ball is (50% % 100%) + (50% * 49.5%) = 74.7%. Category: Interviewing - Brainteasers | Comments are closed
A car travels a distance of 60 miles at an average speed of 30 mph. How fast would the car have to travel the same 60 mile distance home to average 60 mph over the entire trip? Most people say 90 mph but this is actually a trick question! The first leg of the trip covers 60 miles at an average speed of 30 mph. So, this means the car traveled for 2 hours (60/30). In order for the car to average 60 mph over 120 miles, it would have to travel for exactly 2 hours (120/60). Since the car has already traveled for 2 hours, it is impossible for it to average 60 mph over the entire trip. Category: Interviewing - Brainteasers | Comments are closed
Three envelopes are presented in front of you by an interviewer. One contains a job offer, the other two contain rejection letters. You pick one of the envelopes. The interviewer then shows you the contents of one of the other envelopes, which is a rejection letter. The interviewer now gives you the opportunity to switch envelope choices. Should you switch? The answer is yes. Say your original pick was envelope A. Originally, you had a 1/3 chance that envelope A contained the offer letter. There was a 2/3 chance that the offer letter was either in envelope B or C. If you stick with envelope A, you still have the same 1/3 chance. Now, the interviewer eliminated one of the envelopes (say, envelope B), which contained a rejection letter. So, by switching to envelope C, you now have a 2/3 chance of getting the offer and you’ve doubled your chances. Note that you will often get this same question but referring to playing cards (as in 3-Card Monte) or doors (as in Monte Hall/Let’s Make a Deal) instead of envelopes. Category: Interviewing - Brainteasers | Comments are closed
A windowless room has 3 lightbulbs. You are outside the room with 3 switches, each controlling one of the lightbulbs. If you can only enter the room one time, how can you determine which switch controls which lightbulb? Turn on two switches (call them A and B) on and leave them on for a few minutes. Then turn one of them off (switch B) and enter the room. The bulb that is lit is controlled by switch A. Touch the other two bulbs http://www.ibankingfaq.com/category/interviewing-brainteasers/
Page 1 of 4
Investment banking interview brainteasers | IBankingFAQ
30/07/2017, 09*13
(they should be off). The one that is still warm is controlled by switch B. The third bulb (off and cold) is controlled by switch C. Category: Interviewing - Brainteasers | Comments are closed
What is the sum of numbers from 1 to 100? The trick here is that you have 50 pairs which each sum to 101 (e.g. 1+100, 2+99, 3+98, etc.). So, 50 times 101 = 5050. Category: Interviewing - Brainteasers | Comments are closed
You are given 12 balls and a scale. Of the 12 balls, 11 are identical and 1 weighs EITHER slightly more or less. How do you find the ball that is different using the scale only three times AND tell if it is heavier or lighter than the others? Significantly harder than the last question! Weigh 4 vs 4 (1st Weighing). If they are identical then you know that all of 8 of these are “normal” balls. Take 3 “normal” balls and weigh them against 3 of the unweighed balls (2nd Weighing). If they are identical, then the last ball is “different.” Take 1 “normal” ball and weigh against the “different” one (3rd Weighing). Now you know if the “different” ball is heavier or lighter. If, on the 2nd weighing, the scales are unequal then you now know if the “different” ball is heavier (if the 3 non-normal balls were heavier) or lighter (if the 3 non-normal balls were lighter). Take the 3 “non-normal” balls and weigh 1 against the other (3rd Weighing). If they are equal then the third ball not weighed is the “different” one. If they are not equal then either the heavier or lighter ball is “different” depending on if the 3 “non-normal” balls were heavier or lighter in the 2nd Weighing. If, on the 1st Weighing, the balls were not equal then at least you know that the 4 balls not weighed are “normal.” Next, take 3 of the “normal balls” and 1 from the heavier group and weigh against the 1 ball from the lighter group plus the 3 balls you just replaced from the heavier group (2nd Weighing). If they are equal then you know that the “different” ball is lighter and is 1 of the 3 not weighed. Of these 3, weigh 1 against 1 (3rd Weighing) If one is lighter, that is the “different” ball, otherwise, the ball not weighed is “different” and lighter. If, on the 2nd weighing from the preceding paragraph, the original heavier group (containing 3 “normal” balls) is still heavier, then either one of the two balls that were NOT replaced are “different.” Take the one from the heavier side and weigh against a normal ball (3rd Weighing). If it is heavier, it is “different,” and heavier otherwise the ball not weighed is “different” and lighter. If, on the 2nd weighing, the original lighter side is now heavier, then we know that one of the 3 balls we replaced is “different.” Weigh one of these against the other (3rd Weighing). If they are equal, the ball not weighed is “different” and heavier. Otherwise, the heavier ball is the “different” one (and is heavier). If you get this right and can answer within the 30 minutes alloted for the interview, then you probably do deserve the job. Category: Interviewing - Brainteasers | Comments are closed
You are given 12 balls and a scale. Of the 12 balls, 11 are identical and 1 weighs slightly more. How do you find the heavier ball using the scale only three times? http://www.ibankingfaq.com/category/interviewing-brainteasers/
Page 2 of 4
Investment banking interview brainteasers | IBankingFAQ
30/07/2017, 09*13
First, weigh 5 balls against 5 balls (1st Use of Scale). If the scale is equal, then discard those 10 balls and weigh the remaining 2 balls against each other (Second Use of Scale). The heavier ball is the one you are looking for. If on the first weighing (5 vs 5), one group is heavier, then of the heavier group weigh 2 against 2 (2nd Use of Scale). If they are equal, then the 5th ball from the heavier group (the one not weighed) is the one you are looking for. If one of the groups of 2 balls is heaver, then take the heaver group of 2 balls and weigh them against each other (Third Use of Scale). The heavier ball is the one you are looking for. Category: Interviewing - Brainteasers | Comments are closed
What is the angle between the hour-hand and minute-hand of a clock at 3:15? At quarter past the hour, the minute-hand is exactly at 3:00 but the hour-hand has moved 1/4 of the way between 3:00 and 4:00. Therefore 1/4 times 1/12 = 1/48 of the clock. With the clock having 360 degrees, 360/48 = 7.5 degrees. Category: Interviewing - Brainteasers | One comment - (Comments are closed)
You’ve got a 10 x 10 x 10 cube made up of 1 x 1 x 1 smaller cubes. The outside of the larger cube is completely painted red. On how many of the smaller cubes is there any red paint? First, note that the larger cube is made up of 1000 smaller cubes. The easiest way to think about this is how many cubes are NOT painted? 8 x 8 x 8 inner cubes are not painted which equals 512 cubes. Therefore, 1000 – 512 = 488 cubes that have some paint. Alternatively, we can calculate this by saying that two 10 x 10 sides are painted (200) plus two 10 x 8 sides (160) plus two 8 x 8 sides (128). 200 + 160 + 128 = 488. Category: Interviewing - Brainteasers | One comment - (Comments are closed)
Four investment bankers need to cross a bridge at night to get to a meeting. They have only one flashlight and 17 minutes to get there. The bridge must be crossed with the flashlight and can only two bankers at a time. The Analyst can cross in 1 minute, the Associate can cross in 2 minutes, the VP can cross in 5 minutes and the MD takes 10 minutes to cross. How can they all make it to the meeting in time? First, the Analyst takes the flashlight and crosses the bridge with the Associate. This takes 2 minutes. The Analyst then returns across the bridge with the flashlight taking 1 more minute (3 minutes ed so far). The Analyst gives the flashlight to the VP and the VP and MD cross together taking 10 minutes (13 minutes ed so far). The VP gives the flashlight to the Associate, who recrosses the bridge taking 2 minutes (15 minutes ed so far). The Analyst and Associate now cross the bridge together taking 2 more minutes. Now, all are across the bridge at the meeting in exactly 17 minutes. Note, that instead of investment bankers, you’ll often see the same question using of musical bands (usually either the Beatles or U2). Category: Interviewing - Brainteasers | One comment - (Comments are closed)
http://www.ibankingfaq.com/category/interviewing-brainteasers/
Page 3 of 4
Investment banking interview brainteasers | IBankingFAQ
30/07/2017, 09*13
You are given a 3-gallon jug and a 5-gallon jug. How do you use them to get 4 gallons of liquid? Fill the 5-gallon jug completely. Pour the contents of the 5-gallon jug into the 3-gallon jug, leaving 2 gallons of liquid in the 5-gallon jug. Next, dump out the contents of the 3-gallon jug and pour the contents of the 5gallon jug into the 3-gallon jug. At this point, there are 2 gallons in the 3-gallon jug. Fill up the 5-gallon jug and then pour the contents of the 5-gallon jug into the 3-gallon jug until the 3-gallon jug is full. You will have poured 1 gallon, leaving 4 gallons in the 5-gallon jug. Category: Interviewing - Brainteasers | Comments are closed
http://www.ibankingfaq.com/category/interviewing-brainteasers/
Page 4 of 4
8 Tough Brain Teaser Interview Questions and Answers from Google, Apple and Facebook • Career Sidekick
30/07/2017, 19*23
8 Tough Brain Teaser Interview Questions and Answers from Google, Apple and Facebook
Silicon valley tech companies are famous for asking some pretty crazy brain-teaser interview questions… I wanted to find out exactly what these questions involve. And how difficult they are to answer. I spent a day on Glassdoor.com and a few other sites to come up with the 8 hardest and most interesting interview questions out there. And not just from any companies…We’re going to look at 4 tech giants known for having the toughest interviews: 1. Facebook 2. Google 3. Apple 4. LinkedIn Time to see how many you can answer!
Facebook Brain Teaser Interview Questions and Answers: Question 1: A Russian gangster kidnaps you. He puts two bullets in consecutive order in an empty six-round revolver, spins it, points it at your head and shoots. *click* You’re still alive. He then asks you, “do you want me to spin it again and fire or pull the trigger again right away?” For each option, what is the probability that you’ll be shot? Answer… http://careersidekick.com/brain-teaser-job-interview-questions-facebook-google-apple/
Page 1 of 7
8 Tough Brain Teaser Interview Questions and Answers from Google, Apple and Facebook • Career Sidekick
30/07/2017, 19*23
The key hint here is that the bullets were loaded adjacent to each other. There are 4 ways to arrange the revolver with consecutive bullets so that the first shot is blank. These are the possible scenarios: 1. 2. 3. 4.
(xBBxxx) (xxBBxx) (xxxBBx) (xxxxBB)
The other two scenarios would have meant you got shot on the first attempt. (BBxxxx) or (BxxxxB) Now look at the second slot in those 4 possible scenarios above. Your odds of getting shot are 1/4 or 25%. (Only #1 would get you shot) But if you respin… there are 2 bullets remaining and 6 total slots. 2/6 or 33%.
Question 2: You’re about to get on a plane to Seattle. You want to know if it’s raining. You call 3 random friends who live there and ask each if it’s raining. Each friend has a 2/3 chance of telling you the truth and a 1/3 chance of messing with you by lying. All 3 friends tell you that “Yes” it is raining. What is the probability that it’s actually raining in Seattle? Answer… You only need 1 of your friends to be telling the truth for it to be raining in Seattle. It’s fastest just to calculate the odds that all 3 are lying, and it’s not raining. Each friend has a 1/3 chance of lying. Multiply the odds together… you get 1/27 (1/3 * 1/3 * 1/3). We’re not done yet though… 1/27 is the probability that all 3 friends lied at the same time. The probability that at least 1 told you the truth? 26/27 or around a 96% that it’s raining in Seattle.
Google Brain Teaser Interview Questions and Answers: Question 3: You have a 3 gallon jug and 5 gallon jug, how do you measure out exactly 4 gallons? Answer… We know we can’t get the final result in the 3 gallon jug. It’ll overflow. We need to end up with 4 gallons in the 5 gallon jug. First fill the 3 gallon jug. Then pour the 3 gallons into the 5 gallon jug.
http://careersidekick.com/brain-teaser-job-interview-questions-facebook-google-apple/
Page 2 of 7
8 Tough Brain Teaser Interview Questions and Answers from Google, Apple and Facebook • Career Sidekick
30/07/2017, 19*23
Now the 3 gallon jug is empty, and the 5 gallon jug has 3 gallons in it. Fill the 3 gallon jug again. Slowly pour into the 5 gallon jug. Only 2 gallons will fit because it already has 3. Now it’s full. Exactly 1 gallon is left in the 3 gallon jug. Dump out the 5 gallon jug. Pour your 1 gallon into the 5 gallon jug. Fill up the 3 gallon jug one more time and pour it into the 5 gallon jug! You have exactly 4 gallons (and possibly a job at Google)
Question 4: Why are manhole covers round? Answer… Good news: If you’re tired of math questions this one will give you a break. Manhole covers are round because it’s the only shape that cannot fall through itself. The cover can never accidentally fall down the hole. Microsoft has been known to ask this question and according to Glassdoor.com, Google is asking this too now.
Apple Brain Teaser Interview Questions and Answers: Question 5: There are three boxes, one contains only apples, one contains only oranges, and one contains both apples and oranges. The boxes have been incorrectly labeled such that no label identifies the actual contents of its box. Opening just one box, and without looking in the box, you take out one piece of fruit. By looking at the fruit, how can you immediately label all of the boxes correctly? Answer… So, you know all 3 boxes are incorrectly labeled. Go to the box labeled “Apples + Oranges.” Since the label is wrong, it must have one or the other. This is the box to take one piece of fruit from. Whichever comes out is what that box contains. If you took out an apple, the box has only apples. If you took out an orange, vice versa. Here’s where it gets tricky a bit tricky. But we’re almost done… Let’s say you grabbed an apple. Move the “Apples” label over to that box. Now it’s correctly labeled. You know the “Oranges” box is still labeled wrong (because all 3 were labeled wrong to start and you haven’t http://careersidekick.com/brain-teaser-job-interview-questions-facebook-google-apple/
Page 3 of 7
8 Tough Brain Teaser Interview Questions and Answers from Google, Apple and Facebook • Career Sidekick
30/07/2017, 19*23
touched it). And you know it’s not “Apples”. So it has to be “Apples + Oranges”. The last box is “Oranges”. The same process above would work if you had pulled out an orange at the start.
Question 6: You have a 100 coins laying flat on a table, each with a head side and a tail side. 10 of them are heads up, 90 are tails up. You can’t feel, see or in any other way find out which 10 are heads up. Your goal: split the coins into two piles so there are the same number of heads-up coins in each pile. Answer… By pure coincidence… this is a trick my friend Mike showed me last summer. It blew my mind back then but hopefully it’ll make sense as I write it out. You want equal number of heads in each pile. There are currently 10 of them. You don’t know which but it doesn’t matter. All you have to do… take any 10 coins out of the 100, put them into a separate pile, and flip those 10 over. That’s pile #1. Pile #2 is the remaining 90 coins, unflipped. Just leave them. You’re done. Seriously. You can do this with any number of coins. If you had 20 coins, and 18 were heads, you’d need to take 18 of them (it doesn’t matter which) into a separate pile and flip those 18. That’s pile #1. If you had 10 coins and 3 were heads, you’d take 3 random coins into a new pile and flip those 3 for your first pile, and the rest are your second pile. Crazy right? If you don’t believe me just grab some pennies and try it. There are no exceptions and it doesn’t need to be an even amount of “heads” to begin with either. It can also be zero. Or all.
LinkedIn Brain Teaser Interview Questions and Answers: Question 7: You’re in a room with three light switches, each of which controls one of three light bulbs in the next room. You need to determine which switch controls which bulb. All lights are off to begin, and you can’t see into one room from the other. You can inspect the other room only once. How can you find out which switches are connected to which bulbs?
http://careersidekick.com/brain-teaser-job-interview-questions-facebook-google-apple/
Page 4 of 7
8 Tough Brain Teaser Interview Questions and Answers from Google, Apple and Facebook • Career Sidekick
30/07/2017, 19*23
Answer… Let’s call the switches 1, 2, and 3. Leave switch 1 off. Turn switch 2 on for ten minutes. Now turn it off and quickly turn on switch 3. Go into the room and inspect… The bulb that is still warm but not lit up is controlled by switch 2. The one that’s currently lit up is switch 3. The last one is switch 1.
Question 8: How many golf balls would fit into a Boeing 747? Answer… This last one is tough, but they don’t expect you to get an accurate answer. If you get a question like this (and there are a ton of variations- basketballs in a room, cellphones in Manhattan, etc.) they want to see your thought process. The hiring manager is going to look at how you work your way through it and attempt to figure it out. If you can break a problem down into smaller pieces, stay calm, and get an answer that’s not perfect but reasonably close, you’ve done great. They might not even know the answer. They just want to see how you approach something that’s very difficult. Note: For 5 other major things every hiring manager wants to see, check out this article.
On a Practical Note, What Can You Take Away From This? Question 8 above highlights a pretty good point to in your interviews… There are a lot of questions in an interview where the hiring manager values your thought process. Sometimes more than a correct answer. If you’re stumped, talk out loud a bit and explain what you’re thinking. Ask a question if you need to. Try to break it down into smaller pieces. Specific knowledge can be taught but they can’t teach you problem-solving. Show them this and you have a great shot at getting hired! I talk a lot about how to do this and why it’s important in my job interview answers guide. Here’s a quick story: My degree is in Finance, which means I took a good amount of ing classes too. Early in my career I had a phone interview for an ing position. http://careersidekick.com/brain-teaser-job-interview-questions-facebook-google-apple/
Page 5 of 7
8 Tough Brain Teaser Interview Questions and Answers from Google, Apple and Facebook • Career Sidekick
30/07/2017, 19*23
To make the story short, I could not answer even the most basic ing questions. Really simple stuff that you learn your first year in college. Why? It had just been too long since college and I had forgotten even the basics. And I didn’t prepare well for the interview obviously! But I tried to stumble through it and what I could, talking about what I was thinking. Saying things like, “well, this can’t be right because….” I made some progress. But I definitely didn’t have the right answer, even after 5 minutes grinding through it outloud. But I got invited to come in and do a full day on-site interview the next day. The hiring manager liked my approach to breaking down a problem that I didn’t immediately know how to solve. That’s why being transparent and showing your thought process is one of the tips for interviews that you’ll see me say over and over. You can learn to do the same and get far more job offers. The big takeaway: Don’t panic when you get a question you don’t know… use it as an opportunity to show exactly how you work through things. Be confident with it, relax, smile. … you’re giving the hiring manager what they want! UPDATE: If you have interviews coming up and don’t want to leave anything to chance, I’ve created a new guide where you can copy my exact step-by-step method for getting job offers. You can get more details here. Like this post? Pin it to save for next time you need it!
http://careersidekick.com/brain-teaser-job-interview-questions-facebook-google-apple/
Page 6 of 7
30/07/2017, 09*13
You have 100 balls (50 black balls and 50 white balls) and 2 buckets. How do you divide the balls into the two buckets so as to maximize the probability of selecting a black ball if 1 ball is chosen from 1 of the buckets at random? Just to be perfectly clear, you are assuming that one of the two buckets is chosen at random and then one of the balls from that bucket is chosen at random. You want to put 1 black ball in 1 of the buckets and all of the other 99 balls in the other bucket. This gives you just slightly less than a 75% change of having a black ball chosen. The math works as follows: There’s a 50% chance of selecting the bucket containing 1 ball with a 100% chance of selecting a black ball from that bucket. And a 50% chance of selecting the bucket containing 99 balls with a ~49.5% (49/99) chance of selecting a black ball from that bucket. Total probability of selecting a black ball is (50% % 100%) + (50% * 49.5%) = 74.7%. Category: Interviewing - Brainteasers | Comments are closed
A car travels a distance of 60 miles at an average speed of 30 mph. How fast would the car have to travel the same 60 mile distance home to average 60 mph over the entire trip? Most people say 90 mph but this is actually a trick question! The first leg of the trip covers 60 miles at an average speed of 30 mph. So, this means the car traveled for 2 hours (60/30). In order for the car to average 60 mph over 120 miles, it would have to travel for exactly 2 hours (120/60). Since the car has already traveled for 2 hours, it is impossible for it to average 60 mph over the entire trip. Category: Interviewing - Brainteasers | Comments are closed
Three envelopes are presented in front of you by an interviewer. One contains a job offer, the other two contain rejection letters. You pick one of the envelopes. The interviewer then shows you the contents of one of the other envelopes, which is a rejection letter. The interviewer now gives you the opportunity to switch envelope choices. Should you switch? The answer is yes. Say your original pick was envelope A. Originally, you had a 1/3 chance that envelope A contained the offer letter. There was a 2/3 chance that the offer letter was either in envelope B or C. If you stick with envelope A, you still have the same 1/3 chance. Now, the interviewer eliminated one of the envelopes (say, envelope B), which contained a rejection letter. So, by switching to envelope C, you now have a 2/3 chance of getting the offer and you’ve doubled your chances. Note that you will often get this same question but referring to playing cards (as in 3-Card Monte) or doors (as in Monte Hall/Let’s Make a Deal) instead of envelopes. Category: Interviewing - Brainteasers | Comments are closed
A windowless room has 3 lightbulbs. You are outside the room with 3 switches, each controlling one of the lightbulbs. If you can only enter the room one time, how can you determine which switch controls which lightbulb? Turn on two switches (call them A and B) on and leave them on for a few minutes. Then turn one of them off (switch B) and enter the room. The bulb that is lit is controlled by switch A. Touch the other two bulbs http://www.ibankingfaq.com/category/interviewing-brainteasers/
Page 1 of 4
Investment banking interview brainteasers | IBankingFAQ
30/07/2017, 09*13
(they should be off). The one that is still warm is controlled by switch B. The third bulb (off and cold) is controlled by switch C. Category: Interviewing - Brainteasers | Comments are closed
What is the sum of numbers from 1 to 100? The trick here is that you have 50 pairs which each sum to 101 (e.g. 1+100, 2+99, 3+98, etc.). So, 50 times 101 = 5050. Category: Interviewing - Brainteasers | Comments are closed
You are given 12 balls and a scale. Of the 12 balls, 11 are identical and 1 weighs EITHER slightly more or less. How do you find the ball that is different using the scale only three times AND tell if it is heavier or lighter than the others? Significantly harder than the last question! Weigh 4 vs 4 (1st Weighing). If they are identical then you know that all of 8 of these are “normal” balls. Take 3 “normal” balls and weigh them against 3 of the unweighed balls (2nd Weighing). If they are identical, then the last ball is “different.” Take 1 “normal” ball and weigh against the “different” one (3rd Weighing). Now you know if the “different” ball is heavier or lighter. If, on the 2nd weighing, the scales are unequal then you now know if the “different” ball is heavier (if the 3 non-normal balls were heavier) or lighter (if the 3 non-normal balls were lighter). Take the 3 “non-normal” balls and weigh 1 against the other (3rd Weighing). If they are equal then the third ball not weighed is the “different” one. If they are not equal then either the heavier or lighter ball is “different” depending on if the 3 “non-normal” balls were heavier or lighter in the 2nd Weighing. If, on the 1st Weighing, the balls were not equal then at least you know that the 4 balls not weighed are “normal.” Next, take 3 of the “normal balls” and 1 from the heavier group and weigh against the 1 ball from the lighter group plus the 3 balls you just replaced from the heavier group (2nd Weighing). If they are equal then you know that the “different” ball is lighter and is 1 of the 3 not weighed. Of these 3, weigh 1 against 1 (3rd Weighing) If one is lighter, that is the “different” ball, otherwise, the ball not weighed is “different” and lighter. If, on the 2nd weighing from the preceding paragraph, the original heavier group (containing 3 “normal” balls) is still heavier, then either one of the two balls that were NOT replaced are “different.” Take the one from the heavier side and weigh against a normal ball (3rd Weighing). If it is heavier, it is “different,” and heavier otherwise the ball not weighed is “different” and lighter. If, on the 2nd weighing, the original lighter side is now heavier, then we know that one of the 3 balls we replaced is “different.” Weigh one of these against the other (3rd Weighing). If they are equal, the ball not weighed is “different” and heavier. Otherwise, the heavier ball is the “different” one (and is heavier). If you get this right and can answer within the 30 minutes alloted for the interview, then you probably do deserve the job. Category: Interviewing - Brainteasers | Comments are closed
You are given 12 balls and a scale. Of the 12 balls, 11 are identical and 1 weighs slightly more. How do you find the heavier ball using the scale only three times? http://www.ibankingfaq.com/category/interviewing-brainteasers/
Page 2 of 4
Investment banking interview brainteasers | IBankingFAQ
30/07/2017, 09*13
First, weigh 5 balls against 5 balls (1st Use of Scale). If the scale is equal, then discard those 10 balls and weigh the remaining 2 balls against each other (Second Use of Scale). The heavier ball is the one you are looking for. If on the first weighing (5 vs 5), one group is heavier, then of the heavier group weigh 2 against 2 (2nd Use of Scale). If they are equal, then the 5th ball from the heavier group (the one not weighed) is the one you are looking for. If one of the groups of 2 balls is heaver, then take the heaver group of 2 balls and weigh them against each other (Third Use of Scale). The heavier ball is the one you are looking for. Category: Interviewing - Brainteasers | Comments are closed
What is the angle between the hour-hand and minute-hand of a clock at 3:15? At quarter past the hour, the minute-hand is exactly at 3:00 but the hour-hand has moved 1/4 of the way between 3:00 and 4:00. Therefore 1/4 times 1/12 = 1/48 of the clock. With the clock having 360 degrees, 360/48 = 7.5 degrees. Category: Interviewing - Brainteasers | One comment - (Comments are closed)
You’ve got a 10 x 10 x 10 cube made up of 1 x 1 x 1 smaller cubes. The outside of the larger cube is completely painted red. On how many of the smaller cubes is there any red paint? First, note that the larger cube is made up of 1000 smaller cubes. The easiest way to think about this is how many cubes are NOT painted? 8 x 8 x 8 inner cubes are not painted which equals 512 cubes. Therefore, 1000 – 512 = 488 cubes that have some paint. Alternatively, we can calculate this by saying that two 10 x 10 sides are painted (200) plus two 10 x 8 sides (160) plus two 8 x 8 sides (128). 200 + 160 + 128 = 488. Category: Interviewing - Brainteasers | One comment - (Comments are closed)
Four investment bankers need to cross a bridge at night to get to a meeting. They have only one flashlight and 17 minutes to get there. The bridge must be crossed with the flashlight and can only two bankers at a time. The Analyst can cross in 1 minute, the Associate can cross in 2 minutes, the VP can cross in 5 minutes and the MD takes 10 minutes to cross. How can they all make it to the meeting in time? First, the Analyst takes the flashlight and crosses the bridge with the Associate. This takes 2 minutes. The Analyst then returns across the bridge with the flashlight taking 1 more minute (3 minutes ed so far). The Analyst gives the flashlight to the VP and the VP and MD cross together taking 10 minutes (13 minutes ed so far). The VP gives the flashlight to the Associate, who recrosses the bridge taking 2 minutes (15 minutes ed so far). The Analyst and Associate now cross the bridge together taking 2 more minutes. Now, all are across the bridge at the meeting in exactly 17 minutes. Note, that instead of investment bankers, you’ll often see the same question using of musical bands (usually either the Beatles or U2). Category: Interviewing - Brainteasers | One comment - (Comments are closed)
http://www.ibankingfaq.com/category/interviewing-brainteasers/
Page 3 of 4
Investment banking interview brainteasers | IBankingFAQ
30/07/2017, 09*13
You are given a 3-gallon jug and a 5-gallon jug. How do you use them to get 4 gallons of liquid? Fill the 5-gallon jug completely. Pour the contents of the 5-gallon jug into the 3-gallon jug, leaving 2 gallons of liquid in the 5-gallon jug. Next, dump out the contents of the 3-gallon jug and pour the contents of the 5gallon jug into the 3-gallon jug. At this point, there are 2 gallons in the 3-gallon jug. Fill up the 5-gallon jug and then pour the contents of the 5-gallon jug into the 3-gallon jug until the 3-gallon jug is full. You will have poured 1 gallon, leaving 4 gallons in the 5-gallon jug. Category: Interviewing - Brainteasers | Comments are closed
http://www.ibankingfaq.com/category/interviewing-brainteasers/
Page 4 of 4
8 Tough Brain Teaser Interview Questions and Answers from Google, Apple and Facebook • Career Sidekick
30/07/2017, 19*23
8 Tough Brain Teaser Interview Questions and Answers from Google, Apple and Facebook
Silicon valley tech companies are famous for asking some pretty crazy brain-teaser interview questions… I wanted to find out exactly what these questions involve. And how difficult they are to answer. I spent a day on Glassdoor.com and a few other sites to come up with the 8 hardest and most interesting interview questions out there. And not just from any companies…We’re going to look at 4 tech giants known for having the toughest interviews: 1. Facebook 2. Google 3. Apple 4. LinkedIn Time to see how many you can answer!
Facebook Brain Teaser Interview Questions and Answers: Question 1: A Russian gangster kidnaps you. He puts two bullets in consecutive order in an empty six-round revolver, spins it, points it at your head and shoots. *click* You’re still alive. He then asks you, “do you want me to spin it again and fire or pull the trigger again right away?” For each option, what is the probability that you’ll be shot? Answer… http://careersidekick.com/brain-teaser-job-interview-questions-facebook-google-apple/
Page 1 of 7
8 Tough Brain Teaser Interview Questions and Answers from Google, Apple and Facebook • Career Sidekick
30/07/2017, 19*23
The key hint here is that the bullets were loaded adjacent to each other. There are 4 ways to arrange the revolver with consecutive bullets so that the first shot is blank. These are the possible scenarios: 1. 2. 3. 4.
(xBBxxx) (xxBBxx) (xxxBBx) (xxxxBB)
The other two scenarios would have meant you got shot on the first attempt. (BBxxxx) or (BxxxxB) Now look at the second slot in those 4 possible scenarios above. Your odds of getting shot are 1/4 or 25%. (Only #1 would get you shot) But if you respin… there are 2 bullets remaining and 6 total slots. 2/6 or 33%.
Question 2: You’re about to get on a plane to Seattle. You want to know if it’s raining. You call 3 random friends who live there and ask each if it’s raining. Each friend has a 2/3 chance of telling you the truth and a 1/3 chance of messing with you by lying. All 3 friends tell you that “Yes” it is raining. What is the probability that it’s actually raining in Seattle? Answer… You only need 1 of your friends to be telling the truth for it to be raining in Seattle. It’s fastest just to calculate the odds that all 3 are lying, and it’s not raining. Each friend has a 1/3 chance of lying. Multiply the odds together… you get 1/27 (1/3 * 1/3 * 1/3). We’re not done yet though… 1/27 is the probability that all 3 friends lied at the same time. The probability that at least 1 told you the truth? 26/27 or around a 96% that it’s raining in Seattle.
Google Brain Teaser Interview Questions and Answers: Question 3: You have a 3 gallon jug and 5 gallon jug, how do you measure out exactly 4 gallons? Answer… We know we can’t get the final result in the 3 gallon jug. It’ll overflow. We need to end up with 4 gallons in the 5 gallon jug. First fill the 3 gallon jug. Then pour the 3 gallons into the 5 gallon jug.
http://careersidekick.com/brain-teaser-job-interview-questions-facebook-google-apple/
Page 2 of 7
8 Tough Brain Teaser Interview Questions and Answers from Google, Apple and Facebook • Career Sidekick
30/07/2017, 19*23
Now the 3 gallon jug is empty, and the 5 gallon jug has 3 gallons in it. Fill the 3 gallon jug again. Slowly pour into the 5 gallon jug. Only 2 gallons will fit because it already has 3. Now it’s full. Exactly 1 gallon is left in the 3 gallon jug. Dump out the 5 gallon jug. Pour your 1 gallon into the 5 gallon jug. Fill up the 3 gallon jug one more time and pour it into the 5 gallon jug! You have exactly 4 gallons (and possibly a job at Google)
Question 4: Why are manhole covers round? Answer… Good news: If you’re tired of math questions this one will give you a break. Manhole covers are round because it’s the only shape that cannot fall through itself. The cover can never accidentally fall down the hole. Microsoft has been known to ask this question and according to Glassdoor.com, Google is asking this too now.
Apple Brain Teaser Interview Questions and Answers: Question 5: There are three boxes, one contains only apples, one contains only oranges, and one contains both apples and oranges. The boxes have been incorrectly labeled such that no label identifies the actual contents of its box. Opening just one box, and without looking in the box, you take out one piece of fruit. By looking at the fruit, how can you immediately label all of the boxes correctly? Answer… So, you know all 3 boxes are incorrectly labeled. Go to the box labeled “Apples + Oranges.” Since the label is wrong, it must have one or the other. This is the box to take one piece of fruit from. Whichever comes out is what that box contains. If you took out an apple, the box has only apples. If you took out an orange, vice versa. Here’s where it gets tricky a bit tricky. But we’re almost done… Let’s say you grabbed an apple. Move the “Apples” label over to that box. Now it’s correctly labeled. You know the “Oranges” box is still labeled wrong (because all 3 were labeled wrong to start and you haven’t http://careersidekick.com/brain-teaser-job-interview-questions-facebook-google-apple/
Page 3 of 7
8 Tough Brain Teaser Interview Questions and Answers from Google, Apple and Facebook • Career Sidekick
30/07/2017, 19*23
touched it). And you know it’s not “Apples”. So it has to be “Apples + Oranges”. The last box is “Oranges”. The same process above would work if you had pulled out an orange at the start.
Question 6: You have a 100 coins laying flat on a table, each with a head side and a tail side. 10 of them are heads up, 90 are tails up. You can’t feel, see or in any other way find out which 10 are heads up. Your goal: split the coins into two piles so there are the same number of heads-up coins in each pile. Answer… By pure coincidence… this is a trick my friend Mike showed me last summer. It blew my mind back then but hopefully it’ll make sense as I write it out. You want equal number of heads in each pile. There are currently 10 of them. You don’t know which but it doesn’t matter. All you have to do… take any 10 coins out of the 100, put them into a separate pile, and flip those 10 over. That’s pile #1. Pile #2 is the remaining 90 coins, unflipped. Just leave them. You’re done. Seriously. You can do this with any number of coins. If you had 20 coins, and 18 were heads, you’d need to take 18 of them (it doesn’t matter which) into a separate pile and flip those 18. That’s pile #1. If you had 10 coins and 3 were heads, you’d take 3 random coins into a new pile and flip those 3 for your first pile, and the rest are your second pile. Crazy right? If you don’t believe me just grab some pennies and try it. There are no exceptions and it doesn’t need to be an even amount of “heads” to begin with either. It can also be zero. Or all.
LinkedIn Brain Teaser Interview Questions and Answers: Question 7: You’re in a room with three light switches, each of which controls one of three light bulbs in the next room. You need to determine which switch controls which bulb. All lights are off to begin, and you can’t see into one room from the other. You can inspect the other room only once. How can you find out which switches are connected to which bulbs?
http://careersidekick.com/brain-teaser-job-interview-questions-facebook-google-apple/
Page 4 of 7
8 Tough Brain Teaser Interview Questions and Answers from Google, Apple and Facebook • Career Sidekick
30/07/2017, 19*23
Answer… Let’s call the switches 1, 2, and 3. Leave switch 1 off. Turn switch 2 on for ten minutes. Now turn it off and quickly turn on switch 3. Go into the room and inspect… The bulb that is still warm but not lit up is controlled by switch 2. The one that’s currently lit up is switch 3. The last one is switch 1.
Question 8: How many golf balls would fit into a Boeing 747? Answer… This last one is tough, but they don’t expect you to get an accurate answer. If you get a question like this (and there are a ton of variations- basketballs in a room, cellphones in Manhattan, etc.) they want to see your thought process. The hiring manager is going to look at how you work your way through it and attempt to figure it out. If you can break a problem down into smaller pieces, stay calm, and get an answer that’s not perfect but reasonably close, you’ve done great. They might not even know the answer. They just want to see how you approach something that’s very difficult. Note: For 5 other major things every hiring manager wants to see, check out this article.
On a Practical Note, What Can You Take Away From This? Question 8 above highlights a pretty good point to in your interviews… There are a lot of questions in an interview where the hiring manager values your thought process. Sometimes more than a correct answer. If you’re stumped, talk out loud a bit and explain what you’re thinking. Ask a question if you need to. Try to break it down into smaller pieces. Specific knowledge can be taught but they can’t teach you problem-solving. Show them this and you have a great shot at getting hired! I talk a lot about how to do this and why it’s important in my job interview answers guide. Here’s a quick story: My degree is in Finance, which means I took a good amount of ing classes too. Early in my career I had a phone interview for an ing position. http://careersidekick.com/brain-teaser-job-interview-questions-facebook-google-apple/
Page 5 of 7
8 Tough Brain Teaser Interview Questions and Answers from Google, Apple and Facebook • Career Sidekick
30/07/2017, 19*23
To make the story short, I could not answer even the most basic ing questions. Really simple stuff that you learn your first year in college. Why? It had just been too long since college and I had forgotten even the basics. And I didn’t prepare well for the interview obviously! But I tried to stumble through it and what I could, talking about what I was thinking. Saying things like, “well, this can’t be right because….” I made some progress. But I definitely didn’t have the right answer, even after 5 minutes grinding through it outloud. But I got invited to come in and do a full day on-site interview the next day. The hiring manager liked my approach to breaking down a problem that I didn’t immediately know how to solve. That’s why being transparent and showing your thought process is one of the tips for interviews that you’ll see me say over and over. You can learn to do the same and get far more job offers. The big takeaway: Don’t panic when you get a question you don’t know… use it as an opportunity to show exactly how you work through things. Be confident with it, relax, smile. … you’re giving the hiring manager what they want! UPDATE: If you have interviews coming up and don’t want to leave anything to chance, I’ve created a new guide where you can copy my exact step-by-step method for getting job offers. You can get more details here. Like this post? Pin it to save for next time you need it!
http://careersidekick.com/brain-teaser-job-interview-questions-facebook-google-apple/
Page 6 of 7
Related Documents 3h463d
Brain Teaser 141d1i
November 2022 0
Brain 51686n
February 2023 0
Brain To Brain Communication 3t1l2m
April 2022 0
Brain Gym 64x2j
November 2022 0
Brain Maker 514p5a
December 2019 53
Brain Teasers 95u44
December 2019 403More Documents from "Pratibha Gupta" 4d585y
Brain Teaser 141d1i
November 2022 0
Subversion-cheat-sheet-v1.pdf 4263h
November 2019 119
Cost Output Relationship In The Short Run 1u526e
August 2021 0
The Stages Of Internationalization 501o6t
October 2019 63
Limiting Reactants Practice g4x6v
November 2022 0