The probability that a student correctly answers on the first try (the event A)
ID: 3042684 • Letter: T
Question
The probability that a student correctly answers on the first try (the event A) is P(A) = 0.4. If the student answers incorrectly on the first try, the student is allowed a second try to correctly answer the question (the event B). The probability that the student answers correctly on the second try given that he answered incorrectly on the first try is 0.5. Find the probability that the student correctly answers the question on the first or second try. a) 0.20 b) 0.90 c) 0.64 d) 0.70 e) 0.65 f) None of the above.
Explanation / Answer
probability that the student correctly answers the question on the first or second try =P(correctly answer on first)+P(correctly answer on second|incorrect on first) =0.4+0.6*0.5=0.70
option D is correct
Related Questions
Navigate
Integrity-first tutoring: explanations and feedback only — we do not complete graded work. Learn more.