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CBSE Class 12-science Answered

In answering a question on a MCQ test with 4 choices per question, a student knows the answer, guesses or copies the answer. Let 1 half be the probability that he knows the answer 1 fourth be the probability that he guesses and 1 fourth that he copies it. Assuming that a student, who copies the answer, will be correct with the probability 3 over 4 space text and who guesses the answer will be correct with the probability  end text 1 fourth, what is the probability that student knows the answer, given that he answered it correctly? Arjun does not know that answer to one of the questions in the test. The evaluation process has negative marking. Which value would Arjun violate if he resorts of unfair means? How would an act like the above hamper his character development in the coming years?
Asked by Topperlearning User | 20 Aug, 2016, 12:19: AM
answered-by-expert Expert Answer

Let A be the event that he knows the answer, B be the event that he guesses and C be the event that he copies.

Thus, Required probability = P(A/X) =

If Arjun copies the answer, he will be violating the value of honesty in his character. He should not guess the answer as well because that may fetch him negative marking for a wrong guess. He should accept the question the way it is and leave it unanswered as cheating may get him marks in this exam but this habit may not let him develop integrity of character in the long run.

Answered by | 20 Aug, 2016, 02:19: AM

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