SOLUTION: A quiz consists of 5 true/false questions followed by 2 multiple choice questions with four possible answers. Suppose a student makes random guesses for all answers. a) what is th

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Question 430490: A quiz consists of 5 true/false questions followed by 2 multiple choice questions with four possible answers. Suppose a student makes random guesses for all answers.
a) what is the probability that all answers are incorrect?
b)what is the probability that at least one answer in correct?
Answer by ewatrrr(24785) About Me  (Show Source):
You can put this solution on YOUR website!
 

Hi

A quiz consists of 5 true/false questions followed by 

2 multiple choice questions with four possible answers.

Assuming only one of the four possible answers is correct for @ mulitple choice:

P(answering all incorrect) = (.5)^5*(.75)^2 = .0176

P(at least one correct) = 1 - P(none correct) = 1-.0176 = .9824