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15 Google interview questions

Author: Aren Proger 09-22-2020


The selection of new employees for an innovative company is quite tough; prepare for an interview in a few months, as for the most difficult exam.

Here are some facts. Google prefers to recruit graduates from 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 marks obtained 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 your Google office interview.

1. How many golf balls will fit on a school bus?

Position: Product Manager

This is one of the questions the company asks to see how the applicant seeks a solution to a problem. One of the applicants found a good answer: “I pictured a standard school bus 8 feet wide, 6 feet high and 20 feet long: these are approximate dimensions based on my observations of long traffic jams behind the school bus. That means 960 cubic feet, 1728 cubic inches to cubic feet, which means about 1.6 million cubic inches. I estimate 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 would make 660,000 golf balls, but considering the bus seats and other things taking up space, and the ball's spherical shape, I assumed there would be quite a few free space. And I rounded up the value to 500 thousand balls. "

2. How much money will you pay for all the windows in Seattle?

Position: Product Manager

This is one of those questions where you need to call on your ingenuity and give the simplest answer. We would answer: "$ 10 per window".

3. In a country where people want only boys to have children, every family continues to have children until a boy is born. If they have a girl, they have another child. If 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 decision. Imagine that there are 10 families with 10 children: 5 girls, 5 boys (10 in total). Next, 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 5 already born and 2.5 girls to the existing 5 (a total of 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) will be girls. Add 1.25 boys to 7.5 and 1.25 girls to 7.5. (There are 17.5 children in total, of which 8.75 boys and 8.75 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. Suppose a piano needs to be tuned once a week and it takes one hour, and the tuner works 8 hours a day, 5 days a week. Then 40 pianos need to be tuned every week." Our answer is 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 start our answer by asking, "What disaster is planned for today?"

7. How many times per day do the hands of the clock coincide in one 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 large mainframes because it was very easy to find this marker in hex dumps. Most computer educated people should have seen this at least in assembly lessons, which is why Google expects a software developer to know about it. 0xDEADBEAF (dead beef) was used by IBM RS / 6000 systems, Mac OS on a 32-bit PowerPC processor and Commodore Amiga as a magic value for debugging. On Sun Microsystem's Solaris, this meant 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 happened?

Position: software developer

Answer. He got stuck on the curb. (Not nice, right?)

10. You need to check if your friend Bob has your phone number correctly and is recorded at all. But you cannot ask him directly. You need to write the 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 cannot find out your phone number?

Position: software developer

Answer. Since you are only checking, ask him to call at a specific time. If he doesn't, then he doesn't have your number. Too easy? Another answer: "In this case, you need to use the checksum. Let Bob add all the numbers in your number and write the result on the sheet, then give it back to you."

11. You are the captain of a pirate ship and your crew is going to vote on how to divide 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 a ball that is heavier than the rest using a balance scale and only two weights?

Position: Product Manager

Answer. Take 6 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 scales and solve the problem. If there is a heavy ball in the first group of 6 balls, take the 3 that outweighed during the first weigh-in. Place two of these three on the scales. If one outweighs, then you've found it. If they weigh the same, then your ball is the one that you put aside.

13. You have 2 eggs and access to a 100-story building. Eggs can be either very tough or very fragile, which means they can break if dropped from the first floor or not break even if thrown from the 100th floor. Both eggs are exactly the same. You need to figure out which floor of this building will be the highest to keep the eggs intact when they fall from it. The question is: how many tries do you have to make to figure out the highest floor? And while you can only break two eggs.

Position: Product Manager

Answer: The largest number of attempts is 14 times. Instead of breaking up the floors by 10, you need to start from the 14th, then go up 13 more floors, then 12, then 11, then 10, 9, 8, 7, 6, 5, 4, until you will reach the 99th. If the egg broke on the 100th floor, there would be 12 attempts (or 11 if you assume the egg would break on the 100th floor). Suppose, for example, that we found out that 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 - 14 attempts in total.

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 a 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 it. Let's play."

15. You have been reduced to the size of a 5 cent coin, and your mass has been proportionally reduced according to your density. You were thrown into an empty blender glass. The knives will start moving after 60 seconds. What to do?

Position: Product Manager

Answer. This question assesses the applicant's creativity. We would try to break the electric motor.