Question

. The probability of guessing the correct answer to a certain question is 2 . If the probability of not guessing the 2 correct answer is 3 , then find x. 4. In ∆ABC, E is the midpoint of m

Answer 1

Let E denote the event of guessing a correct question and E bar denote the event of not guessing a correct question . Given probability of guessing a certain question is P(E) = (x/2) Hence probability of not guessing answer isP(E bar) = (2/3) P(E) + P(E bar) = 1 x / 2 + 2 / 3 = 1 x / 2 = 1 / 3 ∴x = 2/ 3. Hence x = 2/3.

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