SOLUTION: A quiz has five multiple-choice questions, each with 4 possible answers. If the quiz is solved by guessing, find the probability that at least one answer is correct

Hi

A quiz has five multiple-choice questions, each with 4 possible answers.  

P(guessing answer correctly) = .25

P(guessing incorrectly) = .75

Note: The probability of x successes in n trials is: 

P = nCx*  where p and q are the probabilities of success and failure 

respectively. In this case p=.25and q =.75

nCx = 

P(atleast one correct of the 5 questions) = 1 - P(none correct) = 1 - (.75)^5