12 people are asked questions in succession in a random order and exactly 3 out of 12 people know the answer. The probability that the `6^("th")` person asked is the `2^("nd")` person to know the answer, is

X and Y stand in a line with 6 people,What is the probability that there are 3 persons between them

In a competitive examination, an examinee either guesses or copies or knows the answer to amultiple choice question with four choices. The probability that he makes a guess is 1/3 and the probability that he copies the answer is 1/6. The probability that the answer is correct, given that he copiedit, is 1/8. Find the probability that he knows the answer to the question, given that he correctly answered

A student answers a multiple choice question with 5 alternatives, of which exactly one is correct. The probability that he knows the correct answer is p, 0 lt p lt 1 . If he does not know the correct answer, he randomly ticks one answer. Given that he has answered the question correctly, the probability that he did not tick the answer randomly, is

Four persons are asked the same question by an interviewer.If each has independently a probability 1/6 of answering correctly then the probability that at least one of them answers correctly is

In answering a question on a multiple choice test, a student either knows the answer or guesses. Let 3/4 be the probability that he knows the answer and 1/4 be the probability that he guesses. Assuming that a student who guesses at the answer with probability 1/4. what is the probability that the student knows the answer given that he answers correctly.?

There are n persons (n>=3), among whom are A and B, who are made to stand in a row in random order.Probability that there is exactly one person between A and B is

There are n persons (n ge 3) , among whom are A and B, who are made to stand in a row in random order. Probability that there is exactly one person between A and B is

In answering a question on a multiple choice test a student either knows the answer or guesses. Let the probability that he knows the answer is 3/4 and probability that he guesses is 1/4 . Assuming that a student who guesses the answer and given correct answer is 1/4 . What is the probability that student knows the answer given that he answered it correctly?