How many golf balls will fit in a school bus.
Google has become famous not only for its achievements, but also for the fact that job interviews are conducted there differently than everyone else. You can be assigned a meeting point in a cafe around the corner or on Skype, and the questions will be such that they will make any smart guy sweat.
billiard balls
There are 8 billiard balls. One of them is slightly heavier than the others. What is the minimum number of weighings on a balance without weights to find this ball?
2 weighings. It is necessary to divide all the balls into three parts: 3 balls in two parts and 2 balls in the third part. First, weigh the first two parts of 3 balls. If one of the parts turned out to be heavier, then we weigh any 2 balls from it among ourselves. Either one of them will be the desired ball, or not weighted if they are equal. In case of equal weight of the parts, at the first weighing, the heavier ball will be in the third part of the two balls.
Dead man in the desert
Found in the desert dead man with a match in hand, no trace. What did he die of and under what circumstances?
This question tests how good you are at reconstructing events and juxtaposing facts. The man died from a fall from the plane, which began to lose altitude, and the accident was inevitable. One parachute was not enough for all the passengers, and they drew lots. He got a short match, and he was forced to jump without a parachute.
4 liters of water
Measure out exactly 4 liters if you have a 3 liter jar, a 5 liter jar and unlimited access to water.
Take a 5-liter jar of water and fill a 3-liter jar with water from this jar, then pour out a 3-liter jar. Pour the remaining two liters from the 5 liter jar into the 3 liter jar. Again, draw a full 5-liter jar of water and add water (1 liter) from it to a 3-liter jar.
Thus, 4 liters will remain in a 5-liter jar.
Bear
You have built a house with all sides facing south. Suddenly you saw a bear. What colour is he?
White. Only at the North Pole can all four walls face south.
Pills
The doctor gave the patient 4 tablets - 2 tablets each different kind that cannot be distinguished by external signs. Tablets should be drunk in 2 doses: in the morning, 1 tablet of each type and the same in the evening. If you break the dosage or do not take the pills, the patient will die. So it turned out that the pills were mixed. How to get treatment and survive?
We all know that getting into a company like Google is not so easy for mere mortals, you need to have extraordinary thinking, a sharp lightning-fast mind and, let's say, logical illogicality.
But, if you can solve these 2 Google interview riddles, feel free to send your resume, you will certainly be hired! 🙂
Riddle 1: Blue and red hats
One hundred prisoners are lined up in a column and everyone is put on hats: red or blue flowers. The number of blue and red caps is unknown. Each prisoner sees only the cap in front of the person standing. Starting from the end of the column, the warden asks everyone the color of his cap, and if the prisoner is right, then he is released, and if not, he is executed. At the same time, each next prisoner hears the answer of the previous one, but does not know whether it turned out to be correct or not.
What should the prisoners agree on before the test so that as many people as possible are free?
Riddle 2: 100 people and 1 light bulb
As soon as one of the prisoners says that all 100 of them have been in the punishment cell at least once, they will be released; but if he turns out to be wrong, then everyone is executed. Before this test, the prisoners are given one night to negotiate and determine a strategy.
What should the prisoners think of in order to be released, provided that the light from the punishment cell is not visible from other cells?
Well, how are you doing? Were you able to solve at least one? 🙂 If yes, take off your hat and bow low before the power of your intellect. If not, don't worry, next time you will definitely succeed. In the meantime, let's take a look at clues.
Riddle 1: clue
99 people, and if you're lucky, then all 100 can be saved as follows. The first prisoner, risking his life, names the color of the person in front. Thus, the second person has information about what kind of cap he has on his head. But he must help the next one! Therefore, the prisoners before the test must agree on how they will encrypt the color information if the person in front has it different. For example, if the color of my hat is red, and the next one in the column is also red, then I say: "Red." If the color of the hat of the next one is blue, then you can say: "Red color" or "Red hat". Hearing additional word, the one who stands in front will understand what color he will need to name.
Riddle 2: clue
Prisoners must choose one person as an accountant and adhere to the following rules:
- those who enter the punishment cell for the first time must turn on the light if it is off or do not touch the switch if the light is on;
- those who enter the punishment cell for the second time do not touch the switch at all;
- if the accountant gets into the camera and sees that the light is on, he turns it off and makes +1;
- if the accountant gets into the cell, and the light is off, he does not touch anything.
Once the accountant counts to 99, he can tell the guards that all the prisoners have been in the cell.
We offer to break your head to test your ability for logical and non-standard thinking.
Job seekers who come to work for Google are rumored to be asked to solve two mysteries about prisoners.
Blue and red hats
One hundred prisoners are lined up in a column and everyone is put on hats: red or blue. The number of blue and red caps is unknown. Each prisoner sees only the cap in front of the person standing. Starting from the end of the column, the warden asks everyone the color of his cap, and if the prisoner is right, then he is released, and if not, he is executed. At the same time, each next prisoner hears the answer of the previous one, but does not know whether it turned out to be correct or not.
What should the prisoners agree on before the test so that as many people as possible are free?
100 people and 1 light bulb
100 people from the previous problem were sent to prison again.
All of them are kept in isolated cells, without the ability to communicate with each other. Every day the guard chooses a random prisoner and puts him in a punishment cell for a while. It only has a light bulb and a switch. Each prisoner who ended up in this punishment cell can turn on or turn off the light bulb.
As soon as one of the prisoners says that all 100 of them have been in the punishment cell at least once, they will be released; but if he turns out to be wrong, then everyone is executed. Before this test, the prisoners are given one night to negotiate and determine a strategy.
What should the prisoners think of in order to be released, provided that the light from the punishment cell is not visible from other cells?
Solving the first riddle
99 people, and if you're lucky, then all 100 can be saved as follows. The first prisoner, risking his life, names the color of the person in front. Thus, the second person has information about what kind of cap he has on his head. But he must help the next one! Therefore, the prisoners before the test must agree on how they will encrypt the color information if the person in front has it different. For example, if the color of my hat is red, and the next one in the column is also red, then I say: "Red." If the color of the hat of the next one is blue, then you can say: "Red color" or "Red hat". Hearing an additional word, the one who is in front will understand what color he will need to name ..
The answer to the second riddle
Prisoners must choose one person as an accountant and adhere to the following rules:
those who enter the punishment cell for the first time must turn on the light if it is off or do not touch the switch if the light is on;
those who enter the punishment cell for the second time do not touch the switch at all;
if the accountant gets into the camera and sees that the light is on, he turns it off and makes +1;
if the accountant gets into the cell, and the light is off, he does not touch anything.
Once the accountant counts to 99, he can tell the guards that all the prisoners have been in the cell.
Here are five real-life assignments that were given to candidates at interviews in the largest companies in the tech industry. Before looking at the answers and solutions under the pictures, try to test your strength - maybe you will surprise yourself?
Position 1: Software Engineer at Google
Task
You have 8 balls: 7 weigh the same, and 1 is slightly heavier than the rest. How to determine with the help of scales which ball is heavier if you only have 2 attempts?
Solution
Step 1. Take any 6 balls out of 8
Step 2. Put 3 balls on two scales (thus using the 1st attempt):
A) if the bowls are equal, then the heavier ball must be sought among the two remaining
B) if one bowl outweighed, then the desired ball is among this three
Step 3. Use the 2nd and last attempt. With option A), everything is simple: you need to weigh the two remaining balls to determine the heavier one. In option B), we weigh any 2 balls out of the remaining 3 and then either the scales will immediately show the heavier one, or the bowls will equalize, which means that the 3rd, unweighted ball is the heaviest.
Position 2: Manager at Amazon
There are 5.623 participants in the sports tournament. How many competitions does it take to determine the winner?
Most Popular Answers
A) one competition - it will determine the champion in the final
B) 5.622 competitions: if there should be only one winner from all participants, then from 5.623 you just need to subtract 1.
Alternative Solution
What is important here is not the “correct answer” (if you notice, the condition of the problem is vague, so there may be several solutions), but a logical approach. Therefore, at first it would be good to clarify what kind of participants they are - teams or individual athletes? Then, depending on the answer, ask the next logical question and so on. So you show your ability to think, reason, make decisions.
Position 3: Software Developer at Webtrends
Task
In a completely dark room in a nightstand are 20 different socks of two kinds. What is the minimum number of socks you need to take in order to have a suitable pair among them?
Answer options
A) 3 socks - either 2 of them will be of the same type, 1 of the other, or all 3 will be of the same type. In any case, you will have a couple.
B) none, since the condition says: “20 different socks of two types”, that is, among them there are no two identical ones.
Position 4: Software Engineer / Web Developer at Microsoft
Task
There are 3 boxes in front of you: one contains apples, another contains bananas, and the third contains a mixture of both. All boxes are labeled incorrectly. You can take out one piece of fruit from one box without looking inside. How many times at least do you need to get the fruit to determine the contents of all the baskets?
Answer
Once
Solution
The key is that the boxes are labeled incorrectly, which means that what is written in each is not what is written. That is, in a box marked C (mixture) there can be either only apples (I), or only bananas (B). We get a fruit from there - did you get an apple? So it's a box of apples.
There are 2 boxes left - marked I and B, and you know that this is not true, and box B can contain either apples or a mixture. But after all, we have already identified apples, therefore this is a mixture. Well, in the last box marked I, it turns out, there are bananas.
Position 5: Software Engineer at Raytheon
Task
There are three switches in front of you, but only one turns on the light bulb on the floor below. From where you are, you can't see or hear if it's on fire. How do you know which light switch is on when you can only go downstairs and check it once?
Turn on any of the three switches and wait 5-10 minutes so that the bulb (if it lights up) has time to heat up. Then turn off the first and turn on the second switch, and go down to check yourself. If the light is off, but warm, then the first switch is responsible for it. If it burns now, then the second. And if the cold does not burn, then the third.
Well, how do you like the tasks? And these are still quite solvable, but on Facebook, for example, they ask interview questions for which there are no obvious answers, and it all depends on your resourcefulness and ingenuity.
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As can be seen from the above note, the Google HR department has a fair sense of humor - and shows it in interview questions when selecting candidates for "highly intelligent" positions. The answers to them are ambiguous and may vary, not necessarily repeating the opinion of the editors of Vesti.Ekonomika. The request for originality, productivity and speed of thinking is understandable if we are talking about innovative developments and the planetary scale of their use. Meanwhile, these questions are addressed mainly to such abilities as Calculations and Abstract Logic (to use the terminology of our laboratory's intellectual diagnostic methods). The real business environment makes demands, among other things, on the development of Memory, Erudition, Vocabulary, Information Processing and Spatial Thinking - of course, to varying degrees, however, in our Business IQ test, they can be analyzed within one respondent profile, and his tasks echo the methodology of "Google", being a reflection of modern organizational reality. Editorial site |
If in Russia the majority of applicants would like to work in Gazprom, in the world for several years a similar rating has been headed by Google. The selection of new employees in an innovative company is quite tough; they prepare for an interview several months in advance, as for the most difficult exam.
Here are some facts. Google prefers to recruit among graduates of eight private American universities ("Ivy League"): Brown University, Harvard, Princeton, Pennsylvania University, Dartmouth College, Yale University, Columbia University, Cornell University.
Representatives of the company do not hide the fact that the grades received during the training are important to them, even if the applicant is already over thirty. Last but not least, Google is looking for people who want to change the world.
Below are 15 questions you might hear when you come to an interview at the Google office.
1. How many golf balls will fit on a school bus?
This is one of the questions companies ask to see how the job seeker is looking for a solution to a problem. One applicant found a good answer: “I submitted a standard school bus 8 feet wide, 6 feet high and 20 feet long: these are approximate measurements based on my observations while standing in traffic behind a school bus for a long time. This means 960 cubic feet, 1728 cubic inches in cubic feet, which means about 1.6 million cubic inches.I calculated that the volume of a golf ball is about 2.5 cubic inches (4/3 * pi * 0.85), since the radius of the ball is 0.85 inches Dividing 1.6 million by 2.5 cubic inches comes out to 660,000 golf balls. However, given the seats on the bus and other things that take up space, and the spherical shape of the ball, I assumed that there would be quite a lot between them free space. And I rounded up the value to 500 thousand balls."
2. How much money would you charge to clean all the windows in Seattle?
Position: product manager
This is one of those questions where you need to call for help ingenuity and give the simplest answer. We would answer: "$10 per window".
3. In a country where people only want to have boys, every family continues to have children until a boy is born. If they have a girl, they have another child. If it's a boy, they stop. What is the ratio of boys and girls in such a country?
Position: product manager
The answer to this question caused lively discussions, as a result we came to the following solution. Imagine that there are 10 families with 10 children: 5 girls, 5 boys (10 in total). Then 5 couples with girls will give birth to five more children. Half (2.5) will be girls, half (2.5) will be boys. We add 2.5 boys to the already born 5 and 2.5 girls to the existing 5 (total 15 children, of which 7.5 are boys and 7.5 are girls). Now 2.5 couples with girls need to give birth to 2.5 children. Half (1.25) will be boys and half (1.25) girls. We add 1.25 boys to the already existing 7.5 and 1.25 girls to those 7.5. (There are 17.5 children in total, of which 8.75 are boys and 8.75 are girls.) And so on, adhering to the 50/50 principle.
4. How many piano tuners are there in the world?
Position: product manager
We would say, "As much as the market requires. Let's say that a piano needs to be tuned once a week and it takes one hour, and the tuner works 8 hours a day for 5 days a week. Then there are 40 pianos that require weekly tuning. Our answer: one for every 40 pianos."
5. Why is the manhole cover round?
Position: software developer
Answer. So that it cannot fall inside the hatch during its installation or dismantling (the rectangular cover easily enters the hatch body diagonally).
6. Develop an evacuation plan for San Francisco.
Position: product manager
Answer. Again, here they look at how the applicant approaches the solution of the problem. We would begin our response by asking, "What disaster is planned for today?"
7. How many times a day do the clock hands coincide in the same position?
Position: product manager
Answer. 22 times. From WikiAnswers: 00:00, 1:05, 2:11, 3:16, 4:22, 5:27, 6:33, 7:38, 8:44, 9:49, 10:55, 12:00 , 13:05, 14:11, 15:16, 16:22, 17:27, 18:33,19:38, 20:44, 21:49, 22:55
8. Explain the meaning of the expression Dead beef (literally: dead meat)
Position: software developer
Answer. DEADBEEF is a hexadecimal value that was used for debugging in the days of the big mainframes, because this token was very easy to find in hex dumps. Most people with a computer background should have seen this at least in assembly language classes, which is why Google expects a software developer to know about it. 0xDEADBEAF (dead beef) was used by IBM RS/6000, Mac OS on 32-bit PowerPC processor and Commodore Amiga as debug magic value. On Sun Microsystem's Solaris, this denoted free kernel memory. On OpenVMS running on Alpha processors, DEAD_BEEF can be seen by pressing CTRL-T.
9. The man directed his car to the hotel, but failed. What's happened?
Position: software developer
Answer. He got stuck on the curb. (Unpleasant, right?)
10. You need to check if your phone is recorded correctly and if your friend Bob has recorded it at all. But you can't ask him directly. You need to write a question on a piece of paper and give it to Eve, who will take it to Bob, and then bring back the answer from him. What should you write on a piece of paper (no direct question) so that Bob can understand the message and Eve can't get your phone number?
Position: software developer
Answer. Since you are only checking, ask him to call at a certain time. If he doesn't, then he doesn't have your number. Too easy? Another answer: "In this case, you need to use a checksum. Have Bob add up all the numbers in your number and write the result on a sheet, then send it back to you."
11. You are the captain of a pirate ship and your crew is going to vote on how to share the stolen gold. If less than half of the pirates agree with you, you will die. How do you divide the gold so that you get a good share of the loot, but still stay alive?
Position: technical manager
Answer. It is necessary to divide the loot equally between 51% of the entire team.
12. You have 8 balls of the same size. 7 of them are the same weight, and one weighs a little more than the rest. Find the ball that is heavier than the rest using a balance scale and only two weighings?
Position: product manager
Answer. Take 6 out of 8 balls and place 3 on each side of the scale. If the heavy ball is not in this group of balls, you have 2 more to put on the scale and solve the problem. If the heavy ball is in the first group of 6 balls, take the 3 that outweighed during the first weigh-in. Of these three, put two on the scales. If one outweighs, then you found it. If they weigh the same, then your ball is the one you set aside.
13. You have 2 eggs and access to a 100-story building. Eggs can either be very hard or very brittle, which means that they can break if they fall from the first floor, or not break even if they are thrown from the 100th floor. Both eggs are exactly the same. You need to find out which floor of this building will be the highest in order to keep the eggs intact when falling from it. Q: How many attempts do you have to make to figure out the highest floor? And you can only break two eggs at a time.
Position: product manager
Answer: The greatest number of attempts is 14 times. Instead of breaking floors down by 10, start at 14, then go up another 13 floors, then 12, then 11, then 10, 9, 8, 7, 6, 5, 4, until you reach get to 99. If the egg were to break on the 100th floor, there would be 12 tries (or 11 if you assume the egg breaks on the 100th floor). Suppose, for example, that we figured out that the 49th is the highest floor where the egg did not break, then our attempts are: 14th, 27th, 39th, 50th (the egg broke on the 50th floor ) plus 40, 41, 42, 43, 44, 45, 46, 47, 48 and 49 floors - a total of 14 attempts.
14. Explain what a database is in three sentences for your 8 year old nephew to understand
Position: product manager
Answer. The main purpose of this question is to assess the applicant's ability to explain complex idea in simple terms. Here's our attempt: "A database is a machine that remembers a lot of information about different things. People use it to remember that information when they need to. Let's go play."
15. You were reduced to the size of a 5-cent coin, and your mass was proportionally reduced in accordance with your density. You were thrown into an empty glass of a blender. The knives will start moving after 60 seconds. What to do?
Position: product manager
Answer. This question evaluates the applicant's creativity. We would try to break the electric motor.
