SOLUTION: a jar contains seven black buttons and seven brown buttons if seven buttons are picked at random what is the probability that exactly three if them are black

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Question 1160163: a jar contains seven black buttons and seven brown buttons if seven buttons are picked at random what is the probability that exactly three if them are black
Answer by Boreal(15235) About Me  (Show Source):
You can put this solution on YOUR website!
the denominator is the way to choose 7 items from 14 or 14C7=3432
the numerator is the number of ways to choose 3 black buttons from seven x the way to choose 4 brown buttons from seven. It is 7C3* 7C4, both of which are 35 and their product 1225
the probability is 1225/3432=0.3569