Probability Questions

If 12 identical balls are to be placed in 3 identical boxes, then the probability that one of the boxes contains exactly 3 balls is :

A bag contains 4 red and 6 black balls. A ball is drawn at random from the bag, its colour is observed and this ball along with two additional balls of the same colour are returned to the bag. If now ...

Four persons independently solve a certain problem correctly with probabilities Then the probability that the problem is solved correctly by at least one of them is...

Three boys and two girls stand in a queue. The probability, that the number of boys ahead of every girl is at least one more than the number of girls ahead of her, is

A multiple choice examination has 5 questions. Each question has three alternative answers of which exactly one is correct. The probability that a student will get 4 or more correct answers just by gu...

A box contains 11 tickets numbered from 1 to 11. Two tickets are drawn similtaneously at random.Let E1 denotes the event that the sum of the numbers on the tickets drawn is even and E2 denotes the eve...

If 1 ball is drawn from each of the boxes B1 , B2 and B3 , the probability that all 3 drawn balls are of thesame color is

Consider 5 independent Bernoulli′s trials each with probability of success p. If the probability of at least one failure is greater than or equal to , then p lies in the interval...

An urn contains nine balls of which three are red, four are blue and two are green. Three balls are drawn at random without replacement from the urn. The probability that the three balls have differen...

A signal which can be green or red with probability and respectively, is received by station A and then transmitted to station B. The probability of each station receiving the signal correctly is . If...

In a binomial distribution , if the probability of at least one success is greater than or equal to , then n is greater than...

One ticket is selected at random from 50 tickets numbered 00, 01, 02, .... , 49. Then the probability that the sum of the digits on the selected ticket is 8, given that the product of these digits is ...

A pair of fair dice is thrown independently three times. The probability of getting a score of exactly 9 twice is

Two aeroplanes I and II bomb a target in succession. The probabilities of I and II scoring a hit correctly are 0.3 and 0.2, respectively. The second plane will bomb only if the first misses the target...

At a telephone enquiry system the number of phone cells regarding relevant enquiry follow Poisson distribution with an average of 5 phone calls during 10-minute time intervals. The probability that th...

Three houses are available in a locality. Three persons apply for the houses. Each applies for one house without consulting others. The probability that all the three apply for the same house is...

The probability that A speaks truth is , while this probability for B is . The probability that they contradict each other when asked to speak on a fact is...

A random variable X has the probability distribution: For the events E = {X is a prime number} and F = {X...

The mean and the variance of a binomial distribution are 4 and 2 respectively. Then the probability of 2 successes is

Five horses are in a race. Mr. A selects two of the horses at random and bets on them. The probability that Mr. A selected the winning horse is