The probability of guessing the correct answer to a certain test questions is x/12 . If the probability of not guessing the correct answer to this question is 2/3, then x =
Probability of guessing the correct answer is = P (E) = x/12
Probability of guessing the incorrect answer is = P (not E) = 2/3
P (E) + P (not E) = 1
x/12 + 2/3 = 1
x+8 = 12
x = 4