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zilonis
02-13-2011, 11:12 PM
In a pool of balls, 30% are red balls and 70% are blue balls. You are asked to pick 10 balls. What is the probability of getting 3 red balls and 7 blue balls? What is the probability of getting 5 red balls and 5 blue balls? What is the probability of getting more than 3 red balls.

Thanks!

tkhunny
02-14-2011, 12:39 AM
You are going to need some binomial coefficients.

Hint on the last part: P(more than 3) = 1 - P(three or fewer) = 1 - P(0) - P(1) - P(2) - P(3)