Common information: in answering a question on a multiple-choice test, a student either knows the answer or the student just guesses. suppose that the probability that the student knows the answer is 0.75, and the probability the student doesn't know the answer and guesses is 0.25. assume that there are 5 choices for each multiple-choice question, i. e. the probability that the student who guesses will be correct is 0.20. the student who knows the answer will be correct all the time. what is the conditional probability that the student knew the answer to a question given that the student answered it correctly