Question

Assume that random guesses are made for 2 ​multiple-choice questions on a test with 5 choices for each​ question, so that there are nequals 2 ​trials, each with probability of success​ (correct) given by pequals 0.20 . Find the probability of no correct answers. LOADING... Click on the icon to view the binomial probability table. The probability of no correct answers is nothing . ​

(Round to three decimal places as​ needed.)

Answer 1

Solution:

Let X be the random variable of currect answer in multiple choice questions.

Number of trial n= 2

Probability of correct answer of each trial is 0.20

p = 0.20

Probability of wrong answer to each trial is 0.80

q= 0.80

To find probability of no correct answer that is P(X = 0)

By using Binomial distribution PMF

P(X = 0) = 0.64

The probability of no correct answer is 0.64