GATE Overflow - Recent questions in Probability
http://gateoverflow.in/questions/mathematics/probability
Powered by Question2AnswerThe probability that A hits a target is 1 / 4 and the probability that B hits a target is 1/3
http://gateoverflow.in/121854/probability-that-hits-target-probability-that-hits-target
The probability that A hits a target is 1 / 4 and the probability that B hits a target is 1/3 .<br />
If each fires once and the target is hit only once, what is the probability that A hits the target?Probabilityhttp://gateoverflow.in/121854/probability-that-hits-target-probability-that-hits-targetThu, 16 Mar 2017 15:26:15 +0000probability
http://gateoverflow.in/121747/probability
If from each box of the three boxes containing $3$ white and $3$ black,$2$ white and $2$ black,$1$ white and $3$ black,one ball is drawn at random ,then the probability that $2$ white and $1$ black ball will be drawn ?Probabilityhttp://gateoverflow.in/121747/probabilityThu, 16 Mar 2017 06:05:10 +0000probability
http://gateoverflow.in/121746/probability
There are $N$ persons sitting in a row. Two of them are selected at random.The probability that two selected persons are not together ?Probabilityhttp://gateoverflow.in/121746/probabilityThu, 16 Mar 2017 06:02:26 +0000probability
http://gateoverflow.in/121744/probability
There are four machines and it is known that exactly two of them are faulty .They are tested one by one in a random order till both the faulty machines are identified ,then the probability that only two tests are needed ?Probabilityhttp://gateoverflow.in/121744/probabilityThu, 16 Mar 2017 05:59:59 +0000MEBook
http://gateoverflow.in/121682/mebook
Assume that a fair six-sided die is rolled once. If the value on the die is 1, 2, or 3, the die is rolled a second time.So find the probability that the aggregate of total of values that turn up is at least 6?Probabilityhttp://gateoverflow.in/121682/mebookWed, 15 Mar 2017 12:55:51 +0000probability
http://gateoverflow.in/121543/probability
A man takes a step forward with probability 0.4 and backwards with probability 0.6 .find the probability that at the end of eleven steps he is just one step away from the starting pointProbabilityhttp://gateoverflow.in/121543/probabilityTue, 14 Mar 2017 06:08:44 +0000ISRO 2014- probability [EE]
http://gateoverflow.in/121207/isro-2014-probability-ee
80. A student is to answer 10 out of 13 questions in an examination such that he must choose at least 4 from the first five questions. The number of choices available to him is<br />
(A) 140<br />
(B) 196<br />
<br />
(C) 280<br />
<br />
(D) 346Probabilityhttp://gateoverflow.in/121207/isro-2014-probability-eeFri, 10 Mar 2017 10:00:50 +0000ISRO 2013- probability [EE]
http://gateoverflow.in/121198/isro-2013-probability-ee
Ten percent of screws produced in a certain factory turn out to be defective. Find the probability that in a sample of 10 screws chosen at random, exactly two will be defective.<br />
a) 0.2<br />
<br />
b) 0.25<br />
<br />
c) 0.8<br />
d) 0.3 79.Probabilityhttp://gateoverflow.in/121198/isro-2013-probability-eeFri, 10 Mar 2017 09:07:48 +0000ISRO 2013 Probability [EE]
http://gateoverflow.in/121197/isro-2013-probability-ee
An urn contains 5 black and 5 white balls. The probability of drawing two balls of the same colour<br />
<br />
a) 2/9<br />
<br />
b) 4/9<br />
<br />
c) 1/9<br />
<br />
d) 5/9Probabilityhttp://gateoverflow.in/121197/isro-2013-probability-eeFri, 10 Mar 2017 09:06:31 +0000ISRO 2013- Probability/Leap year [Mech]
http://gateoverflow.in/120893/isro-2013-probability-leap-year-mech
Chance that a leap year selected at random will contain 53 Sundays is<br />
(a) 3/7<br />
(b) 7/2<br />
(c) 7/3<br />
(d) 2/7Probabilityhttp://gateoverflow.in/120893/isro-2013-probability-leap-year-mechWed, 08 Mar 2017 03:45:25 +0000ISRO 2013- Probability [Mech]
http://gateoverflow.in/120891/isro-2013-probability-mech
If the probability for A to fail an examination is 0.2 and that for B is 0.3, then probability that either A of B fail is<br />
(a) 0.5<br />
(b) 0.06<br />
(c) 0.44<br />
(d) 0.38Probabilityhttp://gateoverflow.in/120891/isro-2013-probability-mechWed, 08 Mar 2017 03:42:42 +0000ISRO 2014- Probability [Mech]
http://gateoverflow.in/120812/isro-2014-probability-mech
A purse contains 4 copper coins and 3 silver coins. A second purse contains 6 copper coins and 4 silver coins. A purse is chosen randomly and a coin is taken out of it. What is the probability that it is a copper coin?<br />
<br />
<br />
a) 70/82<br />
<br />
b) 35/70<br />
<br />
c) 41/82<br />
<br />
d) 41/70Probabilityhttp://gateoverflow.in/120812/isro-2014-probability-mechTue, 07 Mar 2017 10:21:31 +0000ISRO 2015- probability [Mech]
http://gateoverflow.in/120801/isro-2015-probability-mech
The probability that a teacher will give an unannounced test during any class is 1/5. If a student is absent twice, then probability that misses at least one test is<br />
<br />
(a) 24/25<br />
<br />
(b) 16/25<br />
<br />
(c) 7/25<br />
<br />
(d) 9/25Probabilityhttp://gateoverflow.in/120801/isro-2015-probability-mechTue, 07 Mar 2017 09:54:57 +0000ISRO 2016 Probability [Mech]
http://gateoverflow.in/120796/isro-2016-probability-mech
A and B are two candidates appearing for an interview by a company. The probability that A is selected is 0.5 and the probability that both A and B are selected is at most 0.3. The probability of B getting selected is<br />
<br />
<br />
<br />
(a) 0.9<br />
<br />
(b) 5 0.3<br />
<br />
(c) S 0.6<br />
<br />
(d) 0.5Probabilityhttp://gateoverflow.in/120796/isro-2016-probability-mechTue, 07 Mar 2017 09:33:22 +0000ISRO 2016 Number of trials [Mech]
http://gateoverflow.in/120795/isro-2016-number-of-trials-mech
There are 20 locks and 20 matching keys. Maximum number of trials required to match all the locks is<br />
<br />
(a) 190<br />
<br />
(b) 210<br />
<br />
(c) 400<br />
<br />
(d) 40Probabilityhttp://gateoverflow.in/120795/isro-2016-number-of-trials-mechTue, 07 Mar 2017 09:31:05 +0000ISRO 2012- Probability [Mech]
http://gateoverflow.in/120790/isro-2012-probability-mech
The probability that A happens is 1/3. the odds against happening A are:<br />
<br />
a) 2:1<br />
<br />
b) 3:2<br />
<br />
c) 1:2<br />
<br />
d) 2:3Probabilityhttp://gateoverflow.in/120790/isro-2012-probability-mechTue, 07 Mar 2017 09:07:04 +0000ISRO 2012: MEch Probability
http://gateoverflow.in/120771/isro-2012-mech-probability
Let E and F be any two events with P(E U F)= 0.8, P(E) = 0.4 and P (E/ F) = 0.3. Then P (F) is <br />
<br />
(a) 3/7<br />
<br />
(b) 4/7<br />
(c) 3/5<br />
<br />
(d) 2/5Probabilityhttp://gateoverflow.in/120771/isro-2012-mech-probabilityTue, 07 Mar 2017 06:52:15 +0000Probability
http://gateoverflow.in/120760/probability
There are two Biased dice of which first dice shows an even number twice as frequently as odd number second dice shows 5, thrice as frequently is any other number. If these dice are rolled together what is the probability of getting---<br />
<br />
1)Sum as 10<br />
<br />
2)Sum more than 10.Probabilityhttp://gateoverflow.in/120760/probabilityTue, 07 Mar 2017 06:17:41 +0000TIFR 2012- Probability
http://gateoverflow.in/120512/tifr-2012-probability
<p>Amar 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, "<strong>Amar told me that India won</strong>".</p>
<p>What probability should Anthony assign to India's win?</p>
<p>(a) 9/16</p>
<p>(b) 6/16</p>
<p>(c) 7/16</p>
<p>(d) 10/16</p>
<p> </p>Probabilityhttp://gateoverflow.in/120512/tifr-2012-probabilitySat, 04 Mar 2017 08:00:10 +0000ISRO 2006- ECE Probability
http://gateoverflow.in/120495/isro-2006-ece-probability
A box contains 5 black and 5 red balls. Two balls are one after another from the box, without replacement. both balls being red is<br />
<br />
a) 1/90<br />
<br />
b) 1/5<br />
<br />
c) 19/90<br />
<br />
d) 2/9Probabilityhttp://gateoverflow.in/120495/isro-2006-ece-probabilitySat, 04 Mar 2017 05:42:51 +0000ISRO 2007- ECE Probability
http://gateoverflow.in/120401/isro-2007-ece-probability
<p>A bag contains eight white and six red marbles. The probability of drawing two marbles of same colour is</p>
<p>a) 8c<sub>2</sub> .6c<sub>2</sub> / 14c<sub>2</sub> </p>
<p>b) 8c<sub>2</sub> /14c<sub>2</sub> + 6c<sub>2</sub> /14c<sub>2</sub></p>
<p>c) 8c<sub>2</sub>.6c<sub>2</sub> /14c<sub>2</sub>.14c<sub>2</sub></p>
<p>d)8c<sub>2</sub> /14c<sub>2</sub> + 6c<sub>2</sub> /12c<sub>2</sub></p>Probabilityhttp://gateoverflow.in/120401/isro-2007-ece-probabilityFri, 03 Mar 2017 06:37:47 +0000ISRO 2008- ECE Probability
http://gateoverflow.in/120242/isro-2008-ece-probability
A husband and wife appear in an interview for two vacancies for same post The. probability of husband getting selected is 1 /5 while the probability of wife getting selected is 1/7. Then the probability that anyone of them getting selected is<br />
<br />
a) 1 /35<br />
<br />
b) 11/35<br />
<br />
c) 12/35<br />
<br />
d) 34/35Probabilityhttp://gateoverflow.in/120242/isro-2008-ece-probabilityThu, 02 Mar 2017 07:52:19 +0000ISRO 2009-ECE Probability
http://gateoverflow.in/120116/isro-2009-ece-probability
A man with n keys wants to open a lock. He tries his keys at random. The expected number of attempts for his success is (keys are replaced after every attempt)<br />
<br />
a) n/2<br />
<br />
b) n<br />
<br />
c) √ n<br />
<br />
d) None of the aboveProbabilityhttp://gateoverflow.in/120116/isro-2009-ece-probabilityWed, 01 Mar 2017 04:20:26 +0000ISRO 2009- ECE Engineering Mathematics
http://gateoverflow.in/120110/isro-2009-ece-engineering-mathematics
A straight line and a circle of radius a are given. A chord is drawn at random to this circle parallel to the given line. Expected length of the chord is<br />
a) 2a<br />
<br />
b) π a<br />
c) π a/2<br />
<br />
d) None of the aboveProbabilityhttp://gateoverflow.in/120110/isro-2009-ece-engineering-mathematicsWed, 01 Mar 2017 04:03:13 +0000which os the following is not a valid probability density?
http://gateoverflow.in/120083/which-os-the-following-is-not-a-valid-probability-density
which os the following is not a valid probability density?<br />
<br />
-0.1<br />
<br />
1<br />
<br />
100<br />
<br />
1.1<br />
<br />
//this question is taken from one of the IIT kanpur interview experience blogs-Probabilityhttp://gateoverflow.in/120083/which-os-the-following-is-not-a-valid-probability-densityTue, 28 Feb 2017 17:25:53 +0000ISRO2012-ECE Probability
http://gateoverflow.in/119982/isro2012-ece-probability
Person X can solve 80% of the ISRO question paper and Person Y can solve 60%. The probability that at least one of them will solve a problem from the question paper, selected at random is :<br />
a. 0.48<br />
<br />
b. 0.70<br />
c. 0.88<br />
<br />
d. 0.92Probabilityhttp://gateoverflow.in/119982/isro2012-ece-probabilityTue, 28 Feb 2017 04:35:23 +0000ISRO 2012- ECE Probability
http://gateoverflow.in/119980/isro-2012-ece-probability
<p><img alt="" src="http://gateoverflow.in/?qa=blob&qa_blobid=6065700306588137035"></p>
<p> </p>
<p>a) 0 &1</p>
<p>b) 1&2</p>
<p>c) 1&4</p>
<p>d) None of these</p>Probabilityhttp://gateoverflow.in/119980/isro-2012-ece-probabilityTue, 28 Feb 2017 04:26:48 +0000sheldon ross
http://gateoverflow.in/119893/sheldon-ross
<p><strong>You know that a certain letter is equally likely to be in any one of three different folders. Let αi be the probability that you will find your letter upon making a quick examination of folder i if the letter is, in fact, in folder i, i = 1, 2, 3. (We may have αi < 1.) Suppose you look in folder 1 and do not find the letter. What is the probability that the letter is in folder 1?</strong></p>Probabilityhttp://gateoverflow.in/119893/sheldon-rossMon, 27 Feb 2017 07:19:54 +0000probability
http://gateoverflow.in/119660/probability
<p><img alt="" height="79" src="http://gateoverflow.in/?qa=blob&qa_blobid=15393637210555024677" width="638"></p>Probabilityhttp://gateoverflow.in/119660/probabilityWed, 22 Feb 2017 14:58:45 +0000ISRO2014-EC Mathematics
http://gateoverflow.in/119647/isro2014-ec-mathematics
<p>Match the following:</p>
<p>A Gaussian distribution 1 Calls on a telephone channel</p>
<p>B Rayleigh distribution 2 Random number</p>
<p>C Poisson distribution 3 Thermal noise</p>
<p>D Uniform distribution 4 Fading channel in wireless communication</p>
<hr>
<p>
<br>
A) A-3, B-1, C-4, D-2</p>
<p>B) A-3, B-4, C-2, D-1</p>
<p>C) A-1, B-4, C-3, D-2</p>
<p>D) A-3, B-4, C-1, D-2</p>
<p> </p>Probabilityhttp://gateoverflow.in/119647/isro2014-ec-mathematicsWed, 22 Feb 2017 10:23:36 +0000ISRO2016 EC Probability
http://gateoverflow.in/119618/isro2016-ec-probability
<p>A person on a trip has a choice between private car and public transport. The probability of using a private car is 0.45. While using public transport, further choice available are bus and metro. Out of which the probability of commuting by a bus is 0.55. In such a situation, the probability (rounded upto two decimals) of using a car, bus and metro respectively would be</p>
<hr>
<p>
<br>
(a) 0.45, 0.30 and 0.25</p>
<p>(b) 0.45, 0.25 and 0.30</p>
<p>(c) 0.45, 0.55 and 0</p>
<p>(d) 0.45, 0.35 and 0.20</p>
<p> </p>Probabilityhttp://gateoverflow.in/119618/isro2016-ec-probabilityWed, 22 Feb 2017 04:36:39 +0000ISI 2016A1
http://gateoverflow.in/119499/isi-2016a1
A standard deck of cards, containing 13 cards in each of 4 suites,<br />
is distributed equally among 4 players.<br />
(a) Show that each player must have at least 4 cards of the same<br />
suite. [5]<br />
(b) Define data structures to represent (i) the deck of cards, and<br />
(ii) a distribution of the cards to the four players. [5]<br />
(c) Using your data structures, write an algorithm which<br />
distributes the deck of cards one by one to the four<br />
players in a cyclical manner. [5Probabilityhttp://gateoverflow.in/119499/isi-2016a1Mon, 20 Feb 2017 16:23:14 +0000GATE2017-2-48
http://gateoverflow.in/118513/gate2017-2-48
<p>If a random variable X has a Poisson distribution with mean 5, then the expectation E[(X+2)<sup>2</sup>] equals ___.</p>Probabilityhttp://gateoverflow.in/118513/gate2017-2-48Tue, 14 Feb 2017 08:31:08 +0000GATE2017-2-31
http://gateoverflow.in/118373/gate2017-2-31
<p>For any discrete random variable $X$, with probability mass function</p>
<p>$P(X=j)=p_j, p_j \geq 0, j \in \{0, \dots , N \}$, and $\Sigma_{j=0}^N \: p_j =1$, define the polynomial function $g_x(z) = \Sigma_{j=0}^N \: p_j \: z^j$. For a certain discrete random variable $Y$, there exists a scalar $\beta \in [0,1]$ such that $g_y(z) = 1- \beta+\beta z)^N$. The expectation of $Y$ is</p>
<ol style="list-style-type:upper-alpha">
<li>$N \beta(1-\beta)$</li>
<li>$N \beta$</li>
<li>$N (1-\beta)$</li>
<li>Not expressible in terms of $N$ and $\beta$ alone</li>
</ol>
<p> </p>Probabilityhttp://gateoverflow.in/118373/gate2017-2-31Tue, 14 Feb 2017 07:13:16 +0000GATE2017-2-26
http://gateoverflow.in/118368/gate2017-2-26
<p>P and Q are considering to apply for a job. The probability that P applies for the job is 1/4, the probability that P applies for the job given that Q applies for the job is 1/2., and the probability that Q applies for the job given that P applies for the job is 1/3. Then the probability that P does not apply for the job given that Q does not apply for this job is</p>
<ol style="list-style-type: upper-alpha;">
<li>4/5</li>
<li>5/6</li>
<li>7/8</li>
<li>11/12</li>
</ol>Probabilityhttp://gateoverflow.in/118368/gate2017-2-26Tue, 14 Feb 2017 07:12:47 +0000GATE2017-1-19
http://gateoverflow.in/118299/gate2017-1-19
Let $X$ be a Gaussian random variable with mean 0 and variance $\sigma ^{2}$. Let $Y$ = $max\left ( X,0 \right )$ where $max\left ( a,b \right )$ is the maximum of $a$ and $b$. The median of $Y$ is ______________ .Probabilityhttp://gateoverflow.in/118299/gate2017-1-19Tue, 14 Feb 2017 07:05:42 +0000Probability
http://gateoverflow.in/117354/probability
Three $N$ bit binary strings $S_1$,$S_2$,$S_3$ are selected in random. What is the probability that result of bit-wise XOR among them contains $k$ $1$'s.i.e. $S_1\oplus S_2\oplus S_3$ = $S$ , No of set bits in $S$ = $k$<br />
<br />
<br />
<br />
is it $\binom{n}{k}\left ( \frac{1}{2} \right )^k\left ( \frac{1}{2} \right )^{n-k}$ ??Probabilityhttp://gateoverflow.in/117354/probabilityWed, 08 Feb 2017 11:57:03 +0000gatebook
http://gateoverflow.in/116857/gatebook
In an examination there are 80 questions each having four choices. Exactly one of these four choices is correct and the other three are wrong. A student is awarded 1 mark for each correct answer, and -0.25 for each wrong answer. If a student ticks the answer of each question randomly, then the expected value of his/her total marks in the examination is.<br />
<br />
(A) -15<br />
<br />
(B) 0<br />
<br />
(C) 5<br />
<br />
(D) 20Probabilityhttp://gateoverflow.in/116857/gatebookTue, 07 Feb 2017 07:29:44 +0000GATE ME-2017 mean value
http://gateoverflow.in/115861/gate-me-2017-mean-value
A fair six faced die is rolled many times. The mean of outcomes is __________Probabilityhttp://gateoverflow.in/115861/gate-me-2017-mean-valueSat, 04 Feb 2017 14:55:07 +0000GATE-2006-18
http://gateoverflow.in/115413/gate-2006-18
<p>We are given a set X = {x<sub>1</sub>, x<sub>2</sub> ...., x<sub>n</sub>} where x<sub>i</sub> = 2<sup>i</sup>. A sample S ⊆ X is drawn by selecting each x<sub>i</sub> independently with probability P<sub>i</sub> = $\frac{1}{2}$. The expected value of the smallest number in sample S is:</p>
<p>A) $\frac{1}{n}$</p>
<p>B) 2</p>
<p>C) $\sqrt{n}$</p>
<p>D) n</p>
<p> </p>Probabilityhttp://gateoverflow.in/115413/gate-2006-18Fri, 03 Feb 2017 15:47:57 +0000How to calculate standard deviation for Normal Distribution calculations using Gate Virtual Calculator?
http://gateoverflow.in/115242/calculate-deviation-distribution-calculations-calculator
Ex. I want to calculate :<br />
<br />
P(21.11<x<26.66) = P(.33<z<2)<br />
<br />
= 0.4772 - 0.1293<br />
<br />
= 0.3497<br />
<br />
<br />
<br />
How to get 0.4772 and 0.1293?Probabilityhttp://gateoverflow.in/115242/calculate-deviation-distribution-calculations-calculatorFri, 03 Feb 2017 10:06:42 +0000probability
http://gateoverflow.in/115009/probability
<p><img alt="" src="http://gateoverflow.in/?qa=blob&qa_blobid=7470174834792035749"></p>Probabilityhttp://gateoverflow.in/115009/probabilityThu, 02 Feb 2017 18:18:48 +0000Testbook 4 Q.no-41
http://gateoverflow.in/112692/testbook-4-q-no-41
<p>#plz explain??<img alt="" src="http://gateoverflow.in/?qa=blob&qa_blobid=11971320695597998489"></p>Probabilityhttp://gateoverflow.in/112692/testbook-4-q-no-41Sat, 28 Jan 2017 20:26:57 +0000Poisson or Binomial distribution
http://gateoverflow.in/112444/poisson-or-binomial-distribution
If 20 markers are drawn from a large number of markers in which 10% are red markers. What is the probability that the number of red markers drawn exceeds the expected number of red markers. (Use Poisson approximation and Binomial theorem). (Upto 3 decimal places)<br />
<br />
the answer should be P(x>2) = 1- P(x=0)- P(x=1)- P(x=2) right?Probabilityhttp://gateoverflow.in/112444/poisson-or-binomial-distributionSat, 28 Jan 2017 12:00:25 +0000The Dice Game
http://gateoverflow.in/112103/the-dice-game
Three Players A, B and C play a game with a single die. The rules of<br />
the game are:<br />
Player A ALWAYS goes first.<br />
A rolls the die. If the die lands showing a 1 then A wins the game.<br />
If A does not throw a 1 then B has a turn.<br />
B rolls a die. If the die landing shows a 2 or 3 then B wins the<br />
game. If B does not throw a 2 or a 3 then C has a turn.<br />
<br />
C rolls the die. If the die lands showing a 4, 5 or 6 then C wins<br />
the game. If C does not throw a 4 or a 5 or a 6 then A starts again.<br />
<br />
This procedure continues until there is a winner.<br />
<br />
Investigate any or all of:<br />
<br />
1. The probabilities of each of A, B or C winning the game.<br />
<br />
2. Who will be the most likely winner?<br />
<br />
3. The most likely length of the game in terms of the number of rolls<br />
of the die to produce the winnerProbabilityhttp://gateoverflow.in/112103/the-dice-gameFri, 27 Jan 2017 17:31:09 +0000Probability
http://gateoverflow.in/111363/probability
A fair coin is tossed ten times in succession. If the first toss produces a head,<br />
then the probability of getting exactly three heads in ten tosses is<br />
<br />
I am doing like :-<br />
<br />
$\frac{1}{2}*n(9,2)*\frac{1}{2}^2\frac{1}{2}^7$<br />
<br />
I am using bionomial distribution here,Now for initial first head,will probability will be (1/2) or will it be 1?It says first produces head,means first head probability is (1/2) or is it (1)?<br />
<br />
After that i will find 2 success if of 9 trials.<br />
<br />
Please help,that inital (1/2) term above is correct ir should it be 1?Probabilityhttp://gateoverflow.in/111363/probabilityThu, 26 Jan 2017 02:41:18 +0000Probability
http://gateoverflow.in/110852/probability
A,B,C and D are four players playing the dice game and who gets the number 5 first wins the game. If A starts first what is the probability that D wins the game in second trail isProbabilityhttp://gateoverflow.in/110852/probabilityWed, 25 Jan 2017 08:52:07 +0000Probability
http://gateoverflow.in/110683/probability
<p><em>Given below are two problems that I had encountered in two different tests. They seem to me as the same type. However, the solutions provided have been done differently. Where am I wrong?</em></p>
<p><em><img alt="" src="http://gateoverflow.in/?qa=blob&qa_blobid=6229195413004414913"></em></p>Probabilityhttp://gateoverflow.in/110683/probabilityTue, 24 Jan 2017 19:26:36 +0000RD SHARMA
http://gateoverflow.in/110397/rd-sharma
There are 4 white and 4 black balls in a bag and 3 balls are drawn at random.If balls of same colour are identical,the probability that none of them are black is,(I am getting 1/14,ans is 1/4)Probabilityhttp://gateoverflow.in/110397/rd-sharmaTue, 24 Jan 2017 10:12:35 +0000Made Easy test series
http://gateoverflow.in/109586/made-easy-test-series
Fifteen coupons are numbered from 1 to 15. Seven coupons are selected at random one at a time with replacement. What is the probability that the largest number appearing on a selected coupon is 9 ?<br />
<br />
<br />
<br />
The solution provided is (3/5)^7 but from the language of question I think there must be at least one 9 <br />
<br />
hence I think the solution should be $\frac{9^{7}-8^{7}}{15^{7}}$Probabilityhttp://gateoverflow.in/109586/made-easy-test-seriesMon, 23 Jan 2017 08:06:26 +0000