Home
Class 12
MATHS
In answering a question on a multiple ch...

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 will be correct with probability `(1)/(4)`. What is the probability that the student knows the answer given that he answered it correctly?

Text Solution

Verified by Experts

The correct Answer is:
`(12)/(13)`
Promotional Banner

Topper's Solved these Questions

  • PROBABILITY

    NCERT GUJARATI|Exercise EXERCISE 3.4|16 Videos

  • PROBABILITY

    NCERT GUJARATI|Exercise EXERCISE 3.5|15 Videos

  • PROBABILITY

    NCERT GUJARATI|Exercise EXERCISE 3.2|18 Videos

  • MATRICES

    NCERT GUJARATI|Exercise Miscellaneous Exercise on Chapter 3|15 Videos

  • RELATIONS AND FUNCTIONS

    NCERT GUJARATI|Exercise MISCLELLANEOUS EXERCISE ON CHAPTER 1|19 Videos

Similar Questions

Explore conceptually related problems

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 an competitive open exam all questions are multiple choice (MCQs) and each question has 4 options, in which one options is always true. The probability of an event that student knows the answer of question is 90%. What is the probability of an event that student gives true answer of questions by guessing ?

Choose the correct answer: The probability that a student is not a swimmer is (1)/(5) out of five students, four are swimmers is

The probability of an event that student gets I, II and III grade in exam is (1)/(10),(3)/(5) and (1)/(4) respectively. Then ......... is the probability that he fails in exam.

A problem in mathematics is given to three students and their respective probabilities of solving the problem are (1)/(2) , (1)/(3) and (1)/(4) . The probability that the problem is solved, is

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?

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 coin falls heads, he answers 'true', if it falls tails, he answers 'false'. Find the probability that he answers at least 12 questions correctly.

Four person independently solve a certain problem correctly with probabilities 1/2,3/4,1/4,1/8dot Then the probability that he problem is solve correctly by at least one of them is

A and B are two students. Their chances of solving a problem correctly are (1)/(3) and (1)/(4) , respectively. If the probability of their making a common error is (1)/(20) and they obtain the same answer, then the probability of their answer to be correct is ..........

A multuple choice examination has 5 questions. Each questions has three alternative answers of which exactly one is correct. The probability that a student will get 4 or more correct answers just be guessing, is