In an examination, 20 questions of true-false type are asked. Suppose a student tosses a fair coin to determine his answer to each question. If the com falls heads, he answers "true1; if it falls tails, he answers "false1. Find the probability that he answers at least 12 questions correctly.

In an examination, 20 questions of true-false type are asked. Suppose a student tosses a fair coin to determine his answer to each question. If the com falls heads, he answers "true1; if it falls tails, he answers "false1. Find the probability that he gives at least two correct answers

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

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

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

In a test an examinee either guesses, copies or knows the answer to multiple choice question with five choices. The probability that he makes a guess is 1/4 and probability that he copies the answer is 1/8 . The probability that his answer is correct given that he copies is 1/10 . Find the probability that he knows the answer to the question given that he correctly answered it:

In an entrance test, there are multiple choice questions. There are four possible answers to each question, of which one is correct. The probability that a student knows the answer to a question is 90%. If the gets the correct answer to a question, then find the probability that he was guessing.

In an entrance test, there are multiple choice questions. There are four possible answers to each question, of which one is correct. The probability that a student knows the answer to a question is 90%. If the gets the correct answer to a question, then find the probability that he was guessing.

There are 5 questions in a multiple choice examination in which each question has 3 possible answers.Find the probability that a student gives 4 correct answers by guess only.

In an entrance examination, a candidate is to answer a multiple choice question which has four alternative solutions. The candidate either guesses the answer or he knows the answer. The probability that he knows the answer is 0.6. The examiner has found that the candidate has answered the question correctly. Find the probability that the candidate knew the answer, given that he answered it correctly.

The probability of guessing atleast 8 correct answers out of 10 true /false questions