January 25, 2014

Are you smart enough to work at Google by William Poundstone



Are you smart enough to work at Google by William Poundstone

[Trick questions, Zen-like riddles, insanely difficult puzzles, and other devious interviewing technique you need to know to get a job anywhere in the new economy]

What number comes next?
10,90, 60,90,70,66,

Forget math. Spell out the numbers in the plain English, which gives the following
ten(3), nine(4), sixty(5), ninety(6), seventy(7), sixty-six (8),
The numbers are in order of how many letters are in their names. The next number should have 9 letters in it. Secondly, look more closely. Ten is not the only number you can spell with three letters. There is one, two and six, but ten is the largest one in three letter block. Same with the rest of the numbers listed in the series. If both conditions needs to meet, the second better answer is ninety-six (if the number should be less than 100). If there is no limitation, the best answer is ten googol.

The word - googole - appeared in the 1940 book that Kasner wrote with James Newman, Mathematics and Imagination. Nine-year old Milton Sirotta and his brother Edwin were talking a stroll one day with their uncle in the New Jersey Palisades. The uncle was Edward Kasner, a Columbia mathematician already what famous as the first Jew to gain tenure in the science at that Ivy league institution. Kasner entertained the boys by talking about a topic calculated to appeal to bookish nine-year olds, namely the number that could be written as a ‘1’ followed by 100 zeros. Kasner challenged his nephew to invent a name for the number. Milton’s suggestion was ‘googol’.

The story behind Google’s google name.
Sean (Anderson) and Larry (Page) were in their office, using the whiteboard, trying to think up aa good name - something that related to the indexing of an immense amount to data. Sean verbally suggested the googolplex and Larry respond verbally with the shortened form, googol (both words are specific large numbers - Googolplex is 10 raised to the power of googol). Sean was seated at his computer so he executed a search of the internet domain name registry database to see it the newly suggested name was still available for registration and use. Sean is not an infallible speller, and he made the mistake of searching for the name spelled as google.com which he found ot be available. Larry liked the name and within hours, he took the step of registering the name google.com for himself and Sergey.


What comes next in the series?
SSS, SCC, C, SC
The series is the letters of the alphabet in a silly code. A as a capital letter, is made of three straight lines. Encode that as SS. B can be written as one straight line and two curved (SCC). C has single curve, D has one straight and one curve (SC). So E being the next letter, which is four straight lines, the next sequence is SSSS

When there is a wind blowing, does a round-trip by plan take more time, less time or the same?
In general, you wouldn’t expect the wind to be following exactly in the direction of travel, nor exactly at ninety degrees to it. The direction would be somewhere in between. You can break the wind’s velocity down into headwind-tailwind and crosswind components. The point is that both components increase the round-trip time. The best wind for round-trip air travelers is no wind at all.


You and your neighbor are holding yard sales on the same day. Both of you plan to sell the exact same item. You plan to put your item on sale for $100. The neighbor had informed you that he is going to put his on sale for $40. The items are in identical condition. What do you, assuming you are not on especially friendly with this neighbor?

The best answer is buy neighbor's item and hide your item until the first one sells,. then put the second item on sale at a reduced price, according to how late in the day it is.

[Google does spell checking: it is not based on dictionaries; it is based on word usage statistics of the entire internet., which is why Google knows how to correct my name, misspelled and Microsoft Word does not.]

You want to have Tim’s number, but you cannot ask him directly. Ann is sitting between you and Tim can pass your note once and Tim can also do the same. Ann who sitting in the middle, should not get to know Tim’s number while passing the message across. What is the strategy.
Answer: Tim, call my phone using the number you got.

If you had a stack of pennies as tall as the Empire state building, could you fit them all in one room?

You have ten thousand Apache servers, and one day to generate $1 million. What do you do?

There are two rabbits, speedy and Sluggo. When they run a 100 meter race, Speedy crosses the finish line while Sluggo ist at 90 meter mark. (Both run at a constant speed). Now we match up in a handicapped race. Speedy has to start from 10 meters behind the start (and run 110 meters) while Sluggo starts at the usual mark and runs 100 meters. Who will win?

Answer: Speedy.

There are three women in bathing suites. Two are sad and one is happy. The sad women are smiling. The happy woman is crying. Explain the situation.

Answer: They are beauty contestants.

What is the next number in the series

1
1 1
2 1
1 2 1 1
1 1 1 2 2 1


Answer: This is the look and say sequence. described by the mathematician John Horton Conway in 1986. Except for the first line, each inventories the line above it. Second line says, there is 1 one. 3rd line says, there are 2 ones. 4th line says, there is 1 two and there is 1 one. 5th line says, 1 one, 1 two, 2 ones. So the next in series should be 3 1 2 2 1 1 (3 ones, 1 two, 2 ones).

1. How do you put a giraffe into a refrigerator?
Correct Answer: Open the refrigerator, put in the giraffe, and close the door. This question tests whether you tend to do simple things in an overly complicated way.
2. How do you put an elephant into a refrigerator?
Did you say, Open the refrigerator, put in the elephant, and close the refrigerator?
Wrong Answer.
Correct Answer: Open the refrigerator, take out the giraffe, put in the elephant and close the door. This tests your ability to think through the repercussions of your previous actions.

3. The Lion King is hosting an animal conference. All the animals attend.... except one. Which animal does not attend?
Correct Answer: The Elephant. The elephant is in the refrigerator. You just put him in there. This tests your memory.
Okay, even if you did not answer the first three questions correctly, you still have one more chance to show your true abilities.
4. There is a river you must cross but it is used by crocodiles, and you do not have a boat. How do you manage it?
Correct Answer: You jump into the river and swim across. Have you not been listening? All the crocodiles are attending the Animal Meeting. This tests whether you learn quickly from your mistakes.

Ref links

This was a course taught at MIT by Bill Jacobs and Curtis Fonger, focusing on technical questions for software engineers.


Other Quiz questions:
100 prisoners are each locked in a room
Who Is the Surgeon?
Monty Hall problem
Dining philosophers problem

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