Probability Questions

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...

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

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 ...

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...

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...

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

Three numbers are chosen at random without replacement from {1, 2, 3, ..... , 8}. The probability that their minimum is 3, given that their maximum is 6, 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...

Two events A and B have probabilities 0.25 and 0.50 respectively. The probabilitity that both A and B occur simultaneoushly is 0.14 Then, the probability that neither A nor B occurs is...

The probability that an event A happens in one trial of an experiment is 0.4. Three independent trials of the experments are performed. The probability that the event A happens at lest ones is...

If A and B are two independent events such that P (A) > 0, and P (B) ≠ 1then is equal to

Fifteen coupons are numbered 1, 2, ......., 15, respectively Seven coupons are selected at random one at a time with replacement. The probability that the largest number appearing om a selected coupon...

Three identical dice are rolled. The probbability that the same number will appear on each of t hem, is

A student appears for tests I, III. The student is successful if he passes either in tests I and III. The probabilities of the student passing in tests I, II and III are p, q and respectively . If the...

The probability that at least one of the events A and B occurs is 0.6. If A and B occur simulta neously with probability 0.2, then P() + P() is...

One hundred identical coins, each with probability $p$ of showing heads, are tossed once. If $P(X = 50) = P(X = 51)$, find the value of $p$.