In answering a question in 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 will be correct with probability `1/4` . What is the probability that a student knows the answer, given that he answered it correctly ?

In a test, an examinee either guesses or copies or knows the answer to a multiple 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 his answer is correct given that he copied it is 1/8. Find the probability that he knew the answer to the question, given that he correctly answered it.

A problem is given to three students, whose chances of solving it are : 1/3, 1/5 and 1/6 . What is the probability that exactly one of them may solve it.

A problem in Mathematics is given to three students whose chances of solving it are : 1/2, 1/4 and 1/5 . What is the probability that at least one of them may solve it?

A problem is given to three children, whose chances of solving it are 1/3 , 1/4 and 1/5 , what is the probability that : Only one of them solves it correctly

The probability of guessing the correct answer to a certain question is x/2 .If the probability of not guessing the correct answer is 2/3 . Find x

A problem in Mathematics is given the three students whose chances of solving it are 1/2, 1/3, 1/4 . What is the probability in the following cases ? : At least one of them solves it.

On a multiple choice examination with three possible answers for each of the five questions, what is the probability that a candidate would get four or more correct answers just by guessing ?