A Pair Of Unbiased Dice Is Rolled Together Till A Sum Of Either 5 Or 7 Is Obtained. The Probability That 5 Comes Before 7 Is

Three six – faced fair dice are thrown together. The probability that the sum of the numbers appearing on the dice is 

k (3 ≤ k ≤ 8) is

If the mean and variance of a binomial variate X are 2 and 1 respectively, then the probability that X takes values at most 3 is

If two events A and B such that P(A’) = 0.3, P(B) = 0.5 and P(A ∩ B) = 0.3, then  is

Seven white bails and three black balls are randomly placed in a row. The probability that no two black balls are placed adjacently equals

If from each of the three boxes containing 3 white and 1 black, 2 white and 2 black, 1 white and 3 black balls, one ball is drawn at random, then the probability that two white and one black ball will be drawn is

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 is

A group of 2n boys and 2n girls is randomly divided into two equal groups. The probability that each group contains the same number of boys and girls is

Let A and B be two events such that P(A) = 0.3 and P(A ∪ B) = 0.8. If Aand B are independent events, then P(B) is

An unbiased dia with faces marked 1, 2, 3, 4, 5 and 6 is rolled four times out of the four faces obtained, the probability that the minimum value is exactly than 2 and the maximum value is exactly 5 is

Each of two persons A and B toss three fair coins. The probability that both get the same number of heads is