SOLUTION: A student takes a 5 question multiple choice exam with four choices for each question. To pass the test the student must score above 70%. What is probability of passing by guessin

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Question 1024476: A student takes a 5 question multiple choice exam with four choices for each question. To pass the test the student must score above 70%. What is probability of passing by guessing? Thanks
Answer by robertb(5830) About Me  (Show Source):
You can put this solution on YOUR website!
Assuming the weights of the five questions are equal, the student has to get 4 or 5 correct answers.
==> probability of passing by guessing is p(4) +p(5) = C%285%2C4%29%2A0.75%5E1%2A0.25%5E4+%2B%0D%0AC%285%2C4%29%2A0.75%5E0%2A0.25%5E5+=+1%2F64, or 1.5625%