SOLUTION: The faces of a 12-sided die are numbered from 1 to 12. What is the probability of rolling 9 at least twice in ten tries?

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Question 981781: The faces of a 12-sided die are numbered from 1 to 12. What is the probability of rolling 9 at least twice in ten tries?
Answer by EasySolvin(10) About Me  (Show Source):
You can put this solution on YOUR website!
Ask the reverse -- what is the probability of rolling at most one 9 in ten tries:
probability of zero 9's
(11/12)^10
probability of one 9
10*(1/12)
(because there are ten ways to do it and each has p = 1/12)
Add these together and then subtract from 1 and you get the probability you seek:
prob(at least two 9's) = 0.200