#1
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Drawing Probablity Question
OK so there are 60 cards in this deck. Seven cards will be selected at random. 4 of the 60 cards are the cards we want.
What is the probability of drawing one when selecting 7 random cards? Probability of drawing two? 3? All four? |
#2
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Re: Drawing Probablity Question
I think the first one would be:
[(4/60 x 55/59 x 54/58 x 53/57 x 52/56 x 51/55 x 50/54) x7] = 26.7% |
#3
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Re: Drawing Probablity Question
There are C(60,7) ways of drawing 7 cards from 60.
C(60,7) = C(56,7) + 4*C(56,6) + 6*C(56,5) + 4*C(56,4) + C(56,3) The first term, C(56,7) is the number of ways to draw 7 cards without using any of the four. The second term, 4*C(56,6) is the number of ways to draw 7 cards using exactly one of the four. And so on. That makes the probability of getting 0 60%, 1 34%, 2 6%, 3 0.38% and 4 0.007%. |
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