Complete question is;
Multiple-choice questions each have 5 possible answers, one of which is correct. Assume that you guess the answers to 5 such questions.
Use the multiplication rule to find the probability that the first four guesses are wrong and the fifth is correct. That is, find P(WWWWC), where C denotes a correct answer and W denotes a wrong answer.
P(WWWWC) =
Answer:
P(WWWWC) = 0.0819
Explanation:
We are told that each question has 5 possible answers and only 1 is correct. Thus, the probability of getting the right answer in any question is =
(number of correct choices)/(total number of choices) = 1/5
Meanwhile,since only 1 of the possible answers is correct, then there will be 4 incorrect answers. Thus, the probability of choosing the wrong answer would be;
(number of incorrect choices)/(total number of choices) = 4/5
Now, we want to find the probability of getting the 1st 4 guesses wrong and the 5th one correct. To do this we will simply multiply the probabilities of each individual event by each other.
Thus;
P(WWWWC) = (4/5) × (4/5) × (4/5) × (4/5) × (1/5) = 256/3125 ≈ 0.0819
P(WWWWC) = 0.0819