In answering a question on a multiple r. choice test, a student either knows the answer or guesses. Let \(\frac{3}{4}\) be the probability that he knows the answer \(\frac{1}{4}\)and be the probability that he guesses.Assuming that a student who guesses at the answer will be correct with probability \(\frac{1}{4}\). What is the probability that the student knows the answer given that he answered it correctly ?
