



 
Phalange, My exam has 15 question and I need to get 10 or more correct to pass. Each question has 3 possible answers and I haven't studied at all so I have to guess on each question. Thus for each question the probability that I get it right is 1/3. You know this is a binomial distribution and hence if X is the number you get correct then Hence to find the probability that I pass is P(X = 10) + P(X = 11) + ... + P(X = 15). Harley  


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