SOLUTION: A test consists of 6 multiple choice questions, each having 5 possible answers, one of which is correct. Assume that you guess the answers to all 6. Find the probability of getting

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Question 1099938: A test consists of 6 multiple choice questions, each having 5 possible answers, one of which is correct. Assume that you guess the answers to all 6. Find the probability of getting less than 2 correct.
Answer by KMST(5328) About Me  (Show Source):
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The coefficients of 0.8W%2B0.2R represent the probability of
being Wrong and being Right on each question.
The coefficients of
%280.8W%2B0.2R%29%5E6==
represent the probability of all the possible different outcomes for the 6-question test:
0.8%5E6 is the probability of 6 wrong answers,
6%2A%280.8%29%5E5%2A0.2 is the probability of 5 wrong answers plus one right,
15%2A%280.8%29%5E4%2A%280.2%29%5E2 is the probability of 4 wrong answers plus 2 right ones,
and so on.
So,the probability of getting less than 2 correct answers is