Question

Shelly guesses on 5 multiple choice test questions in a row. If each question has 3 possible answers, what is the probability that Shelly will guess the 6th question correctly?

Answer 1

`(1)/(3)`

Explanation:

The probability isn't affected by what she guesses on the previous questions.

So basically the question is "what is the probability that Shelly will answer correctly on any one question?"

There are 3 answer choices and 1 is correct, so the probability of getting a correct answer is 1 out of 3, or, 1/3.

Answer 2

1/3

Explanation:

This question is an application of binomial distribution model. If we consider each question as an independent trial, then for each trial there are two possible outcomes, success or failure. Success in the sense that she guesses the question correctly, and failure if the guess is wrong. Now, for each trial or question the probability of success is;

1/3

This is because each question has 3 possible answers and only 1 of them is correct.

Now if Shelly guesses on 5 multiple choice test questions in a row, the probability that she will guess the 6th question correctly is still 1/3. This is because the questions represent independent trials and the probability of success is constant in each trial just like in tossing a coin.