Question

A multiple choice test has 20 questions. Each question has five possible answers, of which one is correct. If a student guesses on every question, find the probability that the student will get exactly 12 correct. Round your answer to four decimal places.

Answer 1

3/25

Explanation:

A multiple choice test has 20 questions and each question has five possible answers, of which one is correct.

Therefore, the probability of getting an answer right by guessing is:

1/5

The probability of getting 12 out of 20 correct is therefore the product of the probability of getting each question right and 12/20:

1/5 * 12/20 = 3/25