SOLUTION: If 20% of population have blue eyes, and 5 people are selected at random, what is the probability that at least 4 of them have blue eyes?

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Question 426852: If 20% of population have blue eyes, and 5 people are selected at random, what is the probability that at least 4 of them have blue eyes?
Answer by sudhanshu_kmr(1152) About Me  (Show Source):
You can put this solution on YOUR website!

probability of having blue eye = 20% = 20/100 = 1/5
probability of not having blue eyes = 1 - 1/5 = 4/5

probability of at least 4 have blue eyes =
probability of exactly 4 have blue eyes + probability of exactly 5 have blue
eyes

= 5C4*(1/5)^4*(4/5)^1 + 5C5*(1/5)^5*(4/5)^0

= 5C4*(1/5)^4*(4/5)^1 + 5C5*(1/5)^5