## Probability Interview Questions

- 0of 0 votes

AnswersThere are 4 closed boxes and one of them has $100 inside. You can open one of the boxes if you pay x dollars.

- sashanksatya January 30, 2019 in United States

If the box you opened is empty, you can keep on opening boxes, but you need to pay x dollars every time.

Up to what amount would you pay?| Report Duplicate | Flag | PURGE

unknown Data Scientist Probability - 0of 0 votes

Answers1) You sell roses. Each rose cost 30 cents to buy and you can sell them for $10 a dozen.

- venkateshumamaheswaran May 08, 2018 in United States

a) How many you need to sale to break even if you bought 600 roses?

b) Tomorrow is holiday - there's 20% likelihood you will sale 600 roses, 50% likelihood of selling 900 roses and 30% likelihood of selling 1200 roses. How many would you buy to maximize profit?| Report Duplicate | Flag | PURGE

Amazon Probability - -2of 2 votes

AnswersRound 4

- sonesh July 12, 2015 in United States

Question 5 : Question 5 : Do you know A/B testing ?, when we tell you some result of an experiment, how do you know the results are accurate ?, actually this question was about the statistics, he asked me many questions to check my statistics knowledge ?| Report Duplicate | Flag | PURGE

Microsoft Software Engineer / Developer Brain Storming Data Mining Math & Computation Matrix Probability Testing - 0of 0 votes

AnswersLet's say you are getting a pack of 2 chips, and you know that both chips are coming from the same , either good or bad company, with equal probability. If you test a first chip and it appears to be good chip, what is the probability that second chip is also good? And at least is this probability is greater than 50% or not?

- leontol May 14, 2015 in United States| Report Duplicate | Flag | PURGE

xyz Data Scientist Probability - 0of 0 votes

AnswersThere are 2 companies making electronic chips: good and bad. Good company is making good chips with probability 80 % and defective chips with probability 20 %, and bad company is making good chips with probability 20 % and defective chips with probability 80 %. If you are getting just one chip, and the probability that it is coming from either of companies is the same, what is the probability that it is good chip?

- leontol May 14, 2015 in United States| Report Duplicate | Flag | PURGE

xyz Data Scientist Probability - 1of 1 vote

AnswersIn basket ball game for a player to win a game

- Aspire November 13, 2014 in United States

challenge 1) 2 out of 3 throws should be basket

challenge 2) 5 out of 8 throws should be basket

which challenge should the player choose so that he might have better chance of winning the game?| Report Duplicate | Flag | PURGE

Amazon Software Engineer / Developer Probability - -3of 5 votes

AnswersTossing a coin ten times resulted in 8 heads and 2 tails. How would you analyze whether a coin is fair? What is the p-value?

- midtownguru November 01, 2013 in United States

In addition, more coins are added to this experiment. Now you have 10 coins. You toss each coin 10 times (100 tosses in total) and observe results. Would you modify your approach to the the way you test the fairness of coins?| Report Duplicate | Flag | PURGE

Google Research Scientist Probability - 1of 1 vote

AnswersHaving an infinite stream of numbers write a function to take an element with equal probability for each.

- chandeepsingh85 September 26, 2013 in United States| Report Duplicate | Flag | PURGE

Google Software Engineer / Developer Probability - 0of 0 votes

AnswersDesign and implement a class, which returns a random string value from a set with an arbitrary probability distribution given by an array of probabilities. Using an existing random number generator with a uniform distribution(e.g., Random.nextFloat()), you return the string for the random float value based on the strings probability distribution.

- chandeepsingh85 September 26, 2013 in United States| Report Duplicate | Flag | PURGE

Google Software Engineer / Developer Probability - 0of 0 votes

AnswersRockets are launched until the first successful launching

- anshul221 September 14, 2013 in United States

has taken place.if this does not occur within 5 attempts,the

experiment is halted and the equipment inspected.suppose that

there is a constant probability of 0.8 of having a successful

launching and that successive attempts are independent.Assume

that the cost of the first launching is K dollars while subsequent

launching cost K/3 dollars.whenever a successful launching take place,a certain amount of information

is obtained which may be expressed as financial gain of,say 'C' dollars.if 'T' is the net cost of this

experiment,find the probability distribution of T?| Report Duplicate | Flag | PURGE

Goldman Sachs Intern Probability - 0of 0 votes

AnswersFind the expectation value of number of times you need to pick numbers to find a number smaller than the number you pick from a hat containing 1 to n.

- shravya.nitk August 22, 2013 in United States for Strats division

case 1: if you replace

case 2: if you don't replace

Expectation values! not probability| Report Duplicate | Flag | PURGE

Goldman Sachs Analyst Probability - -6of 6 votes

AnswersThere are three persons A,B,C .A shots the target 6 times out of 7 shots .B shots 4 out of 5 shots .Then what is the probability of hitting the target twice when 2 persons are selected at random.

- siddharthjain July 29, 2013 in India| Report Duplicate | Flag | PURGE

Amazon SDE1 Probability - 0of 0 votes

AnswersWe toss a fair coin n times. A k-streak of flips is said to occur starting at toss i, if the outcome of all the k flips starting from i th flip is the same. For example, for the sequence HTTTHH, there is a 2-streak occurring at 2 nd toss, there is a 2-streak occurring at 3rd toss, and there is a 2-streak occurring at 5th toss. Here the total number of 2-streaks is 3 in the sequence HTTTHH. What is the expected number of k-streaks which you will see in n tosses of a fair coin ?

- oglA June 21, 2013 in United States| Report Duplicate | Flag | PURGE

Algorithm Math & Computation Probability - 0of 0 votes

AnswersGiven +ve numbers in an array . Put the even #s to the left of the array and the odd to the right side of the array . Don't use extra array.

- meek June 05, 2013 in United States| Report Duplicate | Flag | PURGE

VMWare Inc Java Developer Coding Java Probability - 2of 2 votes

AnswersThe probability of a bus passing through a certain intersection in a time window of 20 min. is 0.9

- Abhinav April 27, 2013 in India

What is the probability of the same bus passing through the same intersection in 5 min.| Report Duplicate | Flag | PURGE

Microsoft Senior Software Development Engineer Probability - 1of 1 vote

Answerswhat is the probability of 5 people with different ages sitting in ascending or descending order at a round table.

- michael.jasey March 25, 2013 in United States| Report Duplicate | Flag | PURGE

SIG (Susquehanna International Group) Analyst Probability - 0of 0 votes

AnswersIn a pocket calculator, a person is randomly typing a 8 digit number. What is the probability that the number looks the same even if the calculator is turned upside down.

- Vikas March 04, 2013 in United States| Report Duplicate | Flag | PURGE

GoDaddy Software Engineer / Developer Probability - 0of 0 votes

AnswersRound 2 :

- sonesh January 03, 2013 in India

Q 2 : You are given finitely many intervals in 1D, you have to design a data structure an efficient data structure which can answer queries of the form “In how many intervals the point P belong ?”, P is an input point, and all intervals are closed. I answer B tree(think why) which is most efficient.| Report Duplicate | Flag | PURGE

Microsoft Software Engineer / Developer Algorithm Data Structures Dynamic Programming Probability Trees and Graphs - -1of 1 vote

AnswersRound 2 :

- sonesh January 03, 2013 in India

Q 1 : You are the supervisor of an airport. What happens is that visitors are not visit your airport, instead they go to another one, which means your airport become unpopular nowadays, Now as a supervisor you need to find out what has happens ?, What went wrong ?,How do you find out ?, What is correct ?, How do you find correct one and at what cost ?| Report Duplicate | Flag | PURGE

Microsoft Software Engineer / Developer Algorithm Behavioral Data Mining Data Structures Experience Ideas Probability Application / UI Design - 0of 0 votes

AnswersTwo trains enter at the opposite sides of a tunnel of length L with speeds 'V'. A particle enters the tunnel at the same time with a speed 'v' and it vibrates in the tunnel[i.e. if it reaches the end of the tunnel then it comes back]. What is the position of the particle by the time the 2 trains meet?

- sai September 04, 2012 in India| Report Duplicate | Flag | PURGE

Amazon Software Engineer / Developer Probability Algorithm - 0of 0 votes

AnswersThere are 1000 balls in a bag, of which 900 are black and 100 are white. I randomly draw 100 balls from the bag. What is the probability that the 101st ball will be black?

- mohit May 05, 2012 in India

a)9/10 b)More than 9/10 but less than 1 c)Less than 9/10but more than 0 d)0 e)1| Report Duplicate | Flag | PURGE

unknown Student student Probability - 0of 0 votes

AnswersAmar and Akbar both tell the truth with probability 3/4 and lie with probability 1/4. Amar watches a test match and talks to Akbar about the outcome. Akbar, in turn, tells Anthony, "Amar told me that India won". What probability should Anthony assign to India's win?

- mohit May 05, 2012 in India

a)9/16 b)6/16 c)7/16 d)10/16 e)None of the above| Report Duplicate | Flag | PURGE

unknown Student student Probability - 0of 0 votes

AnswersYou play a dice rolling game, you have two choices:

- liyiou April 24, 2012 in United States for Risk analysis

1. Roll the dice once and get rewarded the amount of $ equal to the outcome number (e.g, $3 for number "3") and stop the game;

2. You can reject the first reward according to its outcome and roll the dice the second time and get rewarded in the same way and stop the game.

Which strategy should you choose to maximize your reward? (that is what outcomes of the first roll should make you play the second game?)

What is the statistical expectation of reward if you choose that strategy?| Report Duplicate | Flag | PURGE

Analyst Probability - 2of 2 votes

AnswersFive people are to be seated randomly around a circular table. What is the probability of two of them sitting next to each other?

- michael.sapozhnikov March 02, 2012 in United States| Report Duplicate | Flag | PURGE

Bloomberg LP Java Developer Probability - 0of 0 votes

AnswersYou are given C containers, B black balls and an unlimited number of white balls. You want to distribute balls between the containers in a way that every container contains at least one ball and the probability of selecting a white ball is greater or equal to P percent. The selection is done by randomly picking a container followed by randomly picking a ball from it.

- unknown February 16, 2012 in United States

Find the minimal required number of white balls to achieve that.

INPUT

The first line contains 1 <= T <= 10 - the number of testcases.

Each of the following T lines contain three integers C B P separated by a single space 1<= C <= 1000; 0 <= B <= 1000; 0 <= P <= 100;

OUTPUT

For each testcase output a line containing an integer - the minimal number of white balls required. (The tests will assure that it's possible with a finite number of balls)

SAMPLE INPUT

3

1 1 60

2 1 60

10 2 50

SAMPLE OUTPUT

2

2

8

EXPLANATION

In the 1st testcase if we put 2 white balls and 1 black ball in the box the probability of selecting a white one is 66.(6)% which is greater than 60%

In the 2nd testcase putting a single white ball in one box and white+black in the other gives us 0.5 * 100% + 0.5 * 50% = 75%

For the 3rd testcase remember that we want at least one ball in each of the boxes.| Report Duplicate | Flag | PURGE

Facebook Software Engineer / Developer Algorithm Probability - 0of 0 votes

AnswersInput : 4 jars and 50 balls of different colors (Red, Green, Yellow, Blue) where each jar can contain a maximum of 100 balls.

- Saurabh October 15, 2011 in India

Problem : When a user draws a red ball he looses his money while if he draws a ball of some other color his money is doubled. Arrange the balls in such a way that the user has highest probability to loose.| Report Duplicate | Flag | PURGE

Flipkart Software Engineer / Developer Probability

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