<PRE><B>Question 1149363</B>
Probability(P) at least one of them had an irregularity = 1 - P(that none of the 50 ballots had an irregularity)
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This is an application of the Binomial Probability Formula,
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P(k successes out of n trials) = nCk * p^k * (1-p)^(n-k), where nCk = n!/(k! * (n-k)!), k is number of successes, n is the number of trials
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If the problem does not give you the probability of a ballot having an irregularity, then you have to use 50%, that is, p = 0.50
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n = 50 and k = 0 means that 50C0 = 1 and p^0 = 1 but still need p to calculate 1 - p
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