Question 170394: This is bothering me, I answered a math problem, This one
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Bill has been given a 20 question mulitple choice test. He hasnt attended class recently, and there are 5 answers to each question, but only one is correct...what is the probability that he will answer more than five questions on the test correctly?..explain your answer
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I think the answer is  , because you multiply the probability of getting one right, and multiply it 6 times,  or 
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Am I right?
Answer by stanbon(75887)   (Show Source):
You can put this solution on YOUR website! Bill has been given a 20 question mulitple choice test. He hasnt attended class recently, and there are 5 answers to each question, but only one is correct...what is the probability that he will answer more than five questions on the test correctly?..explain your answer
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No, that is not the correct answer.
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It is a binomial problem with n= 20, p = 1/5; x>5
n is the number of trials
p is the probability of success on each trial
x is the number of successes
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P(x>5) = 1 - binomcdf(20,(1/5),4) = 0.37035...
This, from using a TI-83 calculator.
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Cheers,
Stan H.
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