The probability of obtaining a score of 1 correct on a 2-item multiple choice test (4 alternatives per item) by random guessing is
A) 2/16
B) 3/16
C) 4/16
D) 6/16

Question

Quizplus · Accepted Answer

The probability of getting exactly 1 correct answer is calculated by considering the probability of getting one correct and one incorrect answer. The probability of getting one correct answer is 1/4, and the probability of getting one incorrect answer is 3/4. There are 2 ways to arrange one correct and one incorrect answer (CI or IC), so the probability is 2 * (1/4) * (3/4) = 6/16.

The Probability of Obtaining a Score of 1 Correct on a 2-Item