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The 12 Craziest Google Interview Questions

Want to work at Google? Then you’d better be ready to answer some very strange questions — like how many golf balls you can cram into a school bus, or why manhole covers are round.

By (@jr_raphael)

November 4, 2009

Crazy Google Interview QuestionsLanding a job at Google is like hitting geek gold: You get your hands on some of the world’s most high-profile tech innovations, you get to work in a swanky office with cool toys and free food, and you get to personally invade the privacy of millions of users every day.

Okay, I’m (more or less) kidding on that last one, but you get the idea: A gig at Google is an object of desire, and it’s something not so easy to attain. But what exactly does it take to get inside those closely guarded walls? This week, we’re getting a rare glimpse into the process.

An “interview coach” from Seattle has just released 140 questions he swears are regularly used in Google job interviews. They range from the mundane — “Why do you want to join Google?” — to the incredibly strange.

Here are 12 of the oddest ones from the list (and no, we are not making these up).

1. How many golf balls can you fit in a school bus?

Um, is this innuendo? Because if so, you should be advised that — even though it may seem like a good idea at the time — that kind of thing can really hurt.

2. How much should you charge to wash all the windows in Seattle?

Trick question, I assume, designed to gauge any hidden Microsoft loyalties.

3. How many piano tuners are there in the entire world?

Just a guess, but I’m going with “five less than the total number of windows in Seattle.”

4. Every man in a village of 100 married couples has cheated on his wife. Every wife in the village instantly knows when a man other than her husband has cheated, but does not know when her own husband has. The village has a law that does not allow for adultery. Any wife who can prove that her husband is unfaithful must kill him that very day. The women of the village would never disobey this law. One day, the queen of the village visits and announces that at least one husband has been unfaithful. What happens?

The town comes to the realization that all the dudes have been boning the queen?

5. You are shrunk to the height of a nickel and your mass is proportionally reduced so as to maintain your original density. You are then thrown into an empty glass blender. The blades will start moving in 60 seconds. What do you do?

Correct answer: scream, panic, and flail.

6. If you look at a clock and the time is 3:15, what is the angle between the hour and the minute hands?

Based on my calculations, the angle of the dangle is inversely proportional to the heat of the meat.

7. Suppose we have N companies, and we want to eventually merge them into one big company. How many ways are there to merge?

Oh, there are plenty of ways to merge, baby.

8. Why are manhole covers round?

Why does this question make me uncomfortable?

9. A man pushed his car to a hotel and lost his fortune. What happened?

Obvious: booze, blackjack, and bare-assed hookers.

10. Explain the significance of “dead beef.”

It’s the smell that clings to you following that night at the hotel.

11. Design an evacuation plan for San Francisco.

Okay, now I’m really getting worried about what goes on at Google Labs.

12. You have eight balls all of the same size. Seven of them weigh the same, and one of them weighs slightly more. How can you find the ball that is heavier by using a balance and only two weighings?

The bigger question: Why the fuck do I have eight balls?






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Comments

  • potatoboy

    I just read this, and so without looking anything up, I'll attempt real answers. 1) Assume a school bus is 30 feet by 6 feet by 6 feet, and 144 golf balls fit in 1 cubic foot. I come up with 155,520 2) I would charge $20 per hour. 3) I have only seen a few in my life. So my life x the area I live in x same area in the rest of the world = 30,000. 4) The queen kills her husbad the king 5) Since your mass and density are the same, you can either jump out or punch the glass. 6) There are 360 degrees in a cirlce. There are 12 hours. The hour hand has moved 1/4th of one hour, or 7.5 degrees. 7) N! It's a factorial equation. 8) Square ones could turn on an angle and fall in; round ones can't 9) He is playing Monopoly, and hit Boardwalk that has someone else's hotel. 10) Profit. Live beef costs money to raise- loss. 11) Too long to go into here, but it involves ferries and airlifts, not just roads. 12) Take 3 balls, and another 3; put two to the side. Weigh three against three. If one side is heavier, focus on those three. Re-weigh two of those, which will tell you which of those three is heaviest (if the two are the same, the one not weighed is heaviest). If the three and three weigh the same, weigh the two you first set aside.
    How'd I do? =)

    • rjquilantang

      For No. (5), If you were shrunk to a size of a nickel and kept your original density, you wouldn't have much material for brains, bones and all. So you'll do exactly NOTHING. For No. (7), isn't there just 1 way to merge any number of companies? So I think the answer is 1. The N is just there to fool you.

      —Just my two cents.

      • JordanLapp

        4 is wrong, because the queen of the village “visits” which excludes her from the original question.
        10 is wrong too. 0xdeadbeef is the seed for the C rand() function (it's in hex, get it?)

    • http://awantoch.wordpress.com/ Alec

      I don't think we are giving this guy credit for his answers, he did awesome.

    • zelrik

      For 1) I d say more like 1 M from the top of my head assuming the bus is 2x2x10 m^3 and a ball is like 4x4x4cm^3/2 (divided by about 2 because it's a sphere : 4/3 pi D^3/8 /D^3 = 2 where D is the size of one side of the cube or diameter of the sphere). 1m^3 is like 1 000 000 cm^3 so 40/32×10^6. It's very rough since I dont have the correct dimensions.

      For 7) it's certainly not N! it's more like ~(N!)! but I think a detailed calculation is needed.

    • James

      I see your reasoning, but I think you’ve missed the point of the questions. There is no right/wrong answer, and you aren’t expected to actually work any of them out (for example, they don’t give you enough information to do any form of calculations for question 1). They are psychographic questions, designed to determine personality types. Take the piano tuners questions. There is no way to possibly work it out. One possible correct answer would be ‘far less than the number of piano in the world’

      It’s to separate free-thinkers from analytic ‘math-types’ and determine personality traits. ie, look at this ink blot and tell me what you see

      • James

        And for question one, they said FIT, not FILL a bus. So as many balls as you want until the bus is full. Answers like that. 

    • Lauren Ashley2010

      6) where did you get 7.5??? 360/4=90…and you should have learned that in 5th grade… So you are not smarter than a 5th grader.

      • derp

        360/4/12 well skills to read that is something a 1st grader can do

    • derp

      4) isnt really that hard, reduce it to 1 pair of couple and slowly add more couples to it. This is a recursion problem and most people should be able to understand it when its increased to 3 pair of couples.

      Answer is: if there are N husband cheating on their wives, then on the N+1th day, all N husbands will be executed

  • davetan

    I am intrigued and not interested in repeating the obvious answers so here are my offbeat responses:

    1. How many golf balls can you fit in a school bus?
    Depends on how many kids are in it.

    2. How much should you charge to wash all the windows in Seattle?
    Whatever the lowest window washing firm bid I can find is +10 to 20% markup. Then have them do it.

    3. How many piano tuners are there in the entire world?
    I'm sure one of the piano tuners associations has an estimate. So it is simply a matter of calling them up (assuming a Google search doesn't reveal the number.)

    4. Every man in a village of 100 married couples has cheated on his wife. Every wife in the village instantly knows when a man other than her husband has cheated, but does not know when her own husband has. The village has a law that does not allow for adultery. Any wife who can prove that her husband is unfaithful must kill him that very day. The women of the village would never disobey this law. One day, the queen of the village visits and announces that at least one husband has been unfaithful. What happens?

    Nothing. Everyone already knows that everyone is cheating and has deliberately kept quiet so that no proof is possible.

    5. You are shrunk to the height of a nickel and your mass is proportionally reduced so as to maintain your original density. You are then thrown into an empty glass blender. The blades will start moving in 60 seconds. What do you do?
    Meh, you could jump out of there with the reduced effective strength to weight ratio, but you might want to just cry and let yourself get chopped up since no woman would date a 3/4 inch tall man.

    6. If you look at a clock and the time is 3:15, what is the angle between the hour and the minute hands?
    Not enough info to answer because you also need the distance between the clock face and each hand. We do live in a 3D world. The 2D answer is 7.5 degrees.

    7. Suppose we have N companies, and we want to eventually merge them into one big company. How many ways are there to merge?
    Virtually infinity if you consult different attorneys.

    8. Why are manhole covers round?
    Everyone knows round covers prevent the cover from falling in. The question is why do they need to do that? The answer is because people can be stupid and get the city into nasty lawsuits if they weren't protected by idiot proof round covers.

    9. A man pushed his car to a hotel and lost his fortune. What happened?
    The car got impounded when he couldn't pay the parking. The wife got mad when she found out (suspected adultery at the hotel too) and filed for divorce. Between the wife attorneys and fines all the money was lost.

    I got bored after this. Seriously, design an evacuation plan for SF during an interview? Delegate to experts who know how to do it.

    For the real answers, Potatoboy seems to have got most of them right.

  • thefriar

    I can go with potatoboy on everything except #10 seeing as Google is a computer company not to interested in livestock, I'm going to say dead beef has nothing to do with cows but rather is an easily remembered Hexadecimal number.

  • bufancy

    Answer for all the questions: Google it!

  • potatoboy

    Well, since I am intrigued by dead beef, and am not geeky enough to know, I looked it up. Here it be:

    DEADBEEF (“dead beef”) is used by IBM RS/6000 systems, Mac OS on 32-bit PowerPC processors and the Commodore Amiga as a magic debug value. On Sun Microsystems' Solaris, it marks freed kernel memory. On OpenVMS running on Alpha processors, DEAD_BEEF can be seen by pressing CTRL-T.[3]

    Gosh, now why didn't I know that off the top of my head?

  • aaronnaas

    8. Why are manhole covers round?

    The better response is a reversal back at the interviewer: “So they won't fall in. There's another shape with that same feature, do you know it?” Actually there are many. I had heard this retort, and figured it out on my own.

    • Faltriwall

      any 3 d object that has a perfect circle as it's largest 2d cross section i.e. cone sphere etc

      • aaronnaas

        Actually, there are 2D shapes that qualify, other than a circle. Consider a 3 cornered shape.

        Oh, I see that wikipedia already had the scoop at http://en.wikipedia.org/wiki/Manhole_cover

        Quote:
        “A round manhole cover cannot fall through its circular opening, whereas a square manhole cover may fall in if it were inserted diagonally in the hole (A _Reuleaux_ triangle or other _curve of constant width_ would also serve this purpose, but round covers are much easier to manufacture.) In reality, however, the existence of a “lip” holding up the lid means that the underlying hole is smaller than the cover, so that other shapes might suffice.”

  • Name

    the village question: think instead of a village of 2 women and their husbands (last names A and B). A knows Mr B cheated, but when Mrs B doesn't fly into a rage and kill her husband, the only logical conclusion is that B think's A's husband is the bad boy. When B doesn't die that day, her husband is confirmed unfaithful and she kills him. B is thinking similarly, so Mr B dies the 2nd day, too. For three couples, A spends a day oblivious thinking B 'oughta know', but if her husband is faithful, that'd explain B not killing her husband. On the 2nd day, when A doesn't kill her husband, B realizes that it is because A first waited for C and then for B. Day 3, all the husbands die. For a hundred couples, day 100 is a bloodbath.

    • zelrik

      No I am not sure I agree, I think it depends on the number of husbands that are cheating.

  • http://www.facebook.com/people/Joe-Weisman/1386871180 Joe Weisman

    Excuse me, but… if I'm any one of the 100 village wives, I know that all of the other 99 wives have cheating husbands, but (for some extremely strange reason, or just plain denial on my behalf) my own husband is faithful. A one in 100 kind of guy! So the queen shows up and announces that there's at least one cheating husband. At least ONE? That's an understatement… How about 99, queeny? Get real! I then get on with my life of house cleaning, laundry and shopping. Since this experience is equally true for all 100 wives, I don't understand why anything should happen at all?

    • Mito

      Bingo. Nothing happens in the village.

      • dknight

        Actually they could decide to kill the queen and keep the peace.

  • sa12k

    For the balls question, couldn't you just weigh all 8 of them, then weigh one of them. Odds on that the single ball is a lighter ball, so minus 7 times it from the total value. If this value is heavier than the single ball then that is the mass. If it is less, minus it from the total value and then divide by 7 for the other mass. This explanation is bit confusing so I'll use algebra:

    Weight 1: W1 = X+7Y
    Weight 2a: W2a = Y or Weight 2b: W2b = X

    If 2a: W1-(7*W2a) = X (W2a = Y)
    If 2b: (W1-W2b)/7 = Y (W2b = X)

    • dashrb

      It says you have a balance, not a scale. You can't tell how heavy (in units) anything is; you can only compare a collection of balls against another collection of balls for a relative indication of which collection is heavier.

      • microsoft

        what the f r u saying…

  • Devon

    Well actually the Queen is just visiting therefore she is not included in their rituals and she doesnt have to do anything.

  • Loki

    (1)All golf balls smaller than a school bus may fit in it, dumb arses. Lateral thinking anyone?

  • G-man

    6. 3:15 on a clock…both hands point in the exact same direction (at the 3). Hence, the angle between them is 0 degrees. How do you get 7.5 degrees? Seems wrong to me.

    • bob

      It depends on the movement of the clock. Most clocks use a movement that causes the hour hand to move continuously. With such a clock, at 3:15 the hour hand would be 1/4 of the way between the 3 and 4 (7.5). Some (not many) clocks use a movement that will only move the hour hand on the hour. With that kind of clock the difference would be 0. My clock is digital. What hands?

    • hitd

      When the minute hand reaches 15, the hour hand has adanced 7.5 degree( 1/4 of angle b/w 3 and 4).

  • Ptr

    1. Is Tiger driving the buss ? Not a spelling error.

    5. Duck … You are as thin as a nickel, the blades will spin over your head.
    …. Assuming a Sunbeam 4141, the Mother of all Blenders.

    • pavan

      Golf balls are not allowed in a school bus

  • slaith

    About the village problem. say there are hundred couples, every wife knows 99 men have cheated and she hasn't told any of the 99 wives for so long, apparently to avoid death, or maybe to avert her own guilt, cuz if 99 husbands cheated, hopefully not with the same wife, maybe all teh wives are guilty. So when the queen declares one man has been cheating, each wife can list 99 men have been cheating(they already know) hence they do what they've done so far…nothing.

  • dude

    ass hole, testing profanity filter

  • gorpkaiser

    5. You are shrunk to the height of a nickel and your mass is proportionally reduced so as to maintain your original density. You are then thrown into an empty glass blender. The blades will start moving in 60 seconds. What do you do?

    Your mass will decrease by length^3, but the surface area of your hands will only decrease by length^2, so you will be able to climb up the sides just like an insect.

    7. Suppose we have N companies, and we want to eventually merge them into one big company. How many ways are there to merge?

    We must have 2 companies merged before we can merge a 3rd company, and and we must have 3 companies merged before we can merge a 4th, etc. For the first merger, there are C(n, 2) possibilities (n combinations of 2 companies). Then there are (n – 1) companies remaining since 2 have merged into 1. Of these (n – 1) companies, we can merge 2 at a time, C(n – 1, 2). That is the number of ways for the second merger, regardless of the number of ways for the first merger, so the possibilities get multiplied. There will be (n – 1) mergers, so

    total # of possibilities = C(n, 2) * C(n – 1, 2) * C(n – 2, 2) * … * C(2, 2) = n! * (n – 1)! / 2^(n – 1)

  • Ralph

    My question re: faithfulness – who are the men cheating with? The other women? Or all the men gay? or a combo? Cause if they are cheating with the women, then everyone's cheating – so they kill the queen and live cheatily ever after?

  • http://www.mytechinterviews.com/ Aswin

    9. The answer is “The guy was playing monopoly”. The car is the token and he landed on someone else hotel so he had to pay rent which he couldn't afford.

  • vjsharma

    Evacuation plan for any city?
    Example total population is X
    so divide the city into a cricle and and make 4 equal arks in the circle .. now you have EAST, WEST, NORTH, SOUTH WINGS..Assume there are X-10 cars in city/4 so u have .25 cars per ark.. every car can carry atleast 4 persons so from every wing u can drive out 4*(x/4) from east west north south roads of the city and take them to other cities.. dont concentrate them at same point as it will become very hard for police to help a mob..

    Answe B
    caculate the means of transport availble
    Cars, trains, airplanes, Ferrys.. multiply all of them with total carrying ability divide by population u will get the exact number that how many people can be evacuated in one go and how many trips thse modes of transport will have to make. :)

  • amirraffi

    Ugh, most of these questions are fake / lies! People who post these lists are playing basically stupid marketing tricks. See, how it works is this: real Google / Microsoft interview questions are typically RELEVANT for the job. But, those are boring, see? No one wants to read a list of coding questions or something. So, instead, people post these lists of brain teasers that are fun and get passed around. In fact, brain teasers have been banned at both Microsoft and Google for software engineers.

    Take this one: “Why are manholes covers round?” This is a classic MICROSOFT questions, which has since been BANNED at both companies. You really Google would ask this? Come on…

    Fake, fake, fake. Especially for software engineers. If you want to see want Google is really asking, look at CareerCup.com or GlassDoor.com, where people who interviewed at these companies are posting their questions. You'll note the lack of stupid questions like these.

  • hitd

    When the minute hand reaches 15, the hour hand has adanced 7.5 degree( 1/4 of angle b/w 3 and 4).

  • allen

    12) You Put three balls in each beam leaving two out. If they're equal then you can derive it from the two balls easily. Say if one of the sets of three balls is heavier, you take two of the three and put it on the beam. If they're equal then obviously the third one is out and if they're not, well the choice is obvious.

  • Landshark2010

    For question 2, i'm surprised nobody thought what I thought:
    How much should you charge to wash all the windows in Seattle?

    You shouldn't be washing any windows in Seattle because all it does is RAIN! The rain takes care of the windows!

  • Landshark2010

    For question 2, i'm surprised nobody thought what I thought:
    How much should you charge to wash all the windows in Seattle?

    You shouldn't be washing any windows in Seattle because all it does is RAIN! The rain takes care of the windows!

  • fiendly

    I am disliking the amount of people who are not commenting on how awesome the author’s answers are.

  • Peter

    For the village question, wouldn’t the cheating involve the wives too? No one would want to admit anything, so no one would die except the 1 husband?

  • Pietro_Provelone

    For the blender question, If you just climbed on the blade and held on while it spins.  You should be fine.

  • Pliskin

    1. How many golf balls can you fit in a school bus?
    Depending on the size of the golf balls, as many as you’d like until you can’t fit any more.
    2. How much should you charge to wash all the windows in Seattle?
    The net worth of Microsoft divided by the number of windows = price per window.
    3. How many piano tuners are there in the entire world?
    This is a fermi paradox. To work it out requires a lot of assumptions, and I don’t make assumptions.
    4. Every man in a village of 100 married couples has cheated on his wife. Every wife in the village instantly knows when a man other than her husband has cheated, but does not know when her own husband has. The village has a law that does not allow for adultery. Any wife who can prove that her husband is unfaithful must kill him that very day. The women of the village would never disobey this law. One day, the queen of the village visits and announces that at least one husband has been unfaithful. What happens?
    Answer 1: All the men run away, because they are all guilty.
    Answer 2: Because the women don’t want their husband to die, they provide proof to other wives that they slept with their husbands. Eventually, all the husbands die (except for the smart ones who already left!)
    Answer 3: The unhappiest wife immediately takes it upon herself to kill her husband, as so to get a new one. All other wives are then free to keep their cheating husbands.
    5. You are shrunk to the height of a nickel and your mass is proportionally reduced so as to maintain your original density. You are then thrown into an empty glass blender. The blades will start moving in 60 seconds. What do you do?
    Answer 1: I’d ask the dime to give me his 10 cents, weigh in my own 5 cents, and conclude that this is a ridiculous situation.
    Answer 2: Depends on how fast the blades are moving (they might be reaaaaallly slow!).
    6. If you look at a clock and the time is 3:15, what is the angle between the hour and the minute hands?
    There are no hands, it’s digital.
    7. Suppose we have N companies, and we want to eventually merge them into one big company. How many ways are there to merge?
    Three: Peaceful, beneficial merger; Hostile takeover: buy out the majority of shares, become the largest stockholder, and force the company to merge in order to survive; talk to the commanding officer of the other company and suggest they’d be more combat effective if they joined forces.
    8. Why are manhole covers round?
    Because the sewer pipes leading to the surface are round?
    9. A man pushed his car to a hotel and lost his fortune. What happened?
    Answer 1: The hotel sued him for property damage.
    Answer 2: The strenuous physical activity the man endured by pushing the car caused him to have a heart attack and he died.
    10. Explain the significance of “dead beef.”
    Answer 1: Each letter corresponds to a hexadecimal value, obviously.
    Answer 2: Dead beef is significant because both my jacket and diet are made from it.
    11. Design an evacuation plan for San Francisco.
    Using a plethora of high grade explosives, detonate them simultaneously along the fault lines, freeing San Francisco from the rest of the plate (or submerging it… either works).
    12. You have eight balls all of the same size. Seven of them weigh the same, and one of them weighs slightly more. How can you find the ball that is heavier by using a balance and only two weighings?
    I would use the balance to beat the answer out of the tester who new which ball weighed more. I would then double check his answer by weighing it against two randomly selected, average weight balls.

  • http://javarevisited.blogspot.com/2011/01/how-classpath-work-in-java.html JP@ classpath in Java

    Google has been known for its tough and weird interview questions but they do respect classics like Data Structure, Operating systems, programming and software design. here are some of my favorite google interview questions asked on software Engineer interview  http://javarevisited.blogspot.com/2012/01/google-interview-questions-answers-top.html

  • http://tutiez.com/ pranav

    Wow , thanks for sharing this wonderful list.