Question 616963: A card is drawn from a deck of cards numbered 1-20. The card is NOT replaced and another card is drawn. Find the probability that a prime number is drawn and then a composite number. I am totally lost...Please help...thank you
Found 2 solutions by ewatrrr, stanbon:
Answer by ewatrrr(24785)   (Show Source):
You can put this solution on YOUR website!
Hi,
A card is drawn from a deck of  cards numbered 1-20 w/o replacement:
Prime: 1, 2, 3, 5, 7, 11, 13, 17, 19 || 9 total
Composite: 4, 6, 8, 9, 10, 12, 14, 15, 16, 18, 20 || 11 total
P(prime and then composite) =
Answer by stanbon(75887)  (Show Source):
You can put this solution on YOUR website! A card is drawn from a deck of cards numbered 1-20. The card is NOT replaced and another card is drawn. Find the probability that a prime number is drawn and then a composite number. I am totally lost...Please help...thank you
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The primes are 2,3,5,7,11,13,17,19
Non-primes are 1,4,6,8,9,10,12,14,15,16,18,20
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P(select prime, then non-prime) = (8/20)(12/19) = (2/5)(12/19) = 24/95
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Cheers,
Stan H.
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