SOLUTION: A multiple choice trivia quiz has 10 questions, each with 5 possible answers. If someone guesses each answer randomly, what is the probability of them getting one or two correct an

Algebra ->  Probability-and-statistics -> SOLUTION: A multiple choice trivia quiz has 10 questions, each with 5 possible answers. If someone guesses each answer randomly, what is the probability of them getting one or two correct an      Log On


   

Question 875860: A multiple choice trivia quiz has 10 questions, each with 5 possible answers. If someone guesses each answer randomly, what is the probability of them getting one or two correct answers?
Answer by ewatrrr(24785) About Me  (Show Source):
You can put this solution on YOUR website!
p = .2, n = 10
P(1 0r 2) = 10C1(.2)^1(.8)^9 + 10C2(.2)^2(.8)^8
Using
P+%28x%29=+highlight_green%28nCx%29%28p%5Ex%29%28q%29%5E%28n-x%29+
p and q are the probabilities of success and failure respectively.
In this case p= .2 and q = .8 and n = 10
nCx+=+%28n%21%29%2Fx%21%28n+-+x%29%21%29