Question 426480
nCr=combination of n things taken r at a time. Find the coefficient for a certain binomial expansion.
p=.8, f=.2
1-.8^15=.9648 probability that at least one person fails the test.
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15C5*f^5p^10
=3003*f^5p^10
=.1032 probability that exactly 5 people fail.
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Ed