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Probability

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Probability

by pkw209 » Wed Apr 21, 2010 3:05 pm
What is the probability of selecting a red card or a 5 from a standard deck of 52 cards?

a) 7/13

b) 6/17

c) 1/4

d) 2/5

e) 3/8
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by grockit_andrea » Wed Apr 21, 2010 4:31 pm
I believe the answer here is A, assuming that a standard deck is 4 suits of 13 cards each. In that standard deck, 2 of the 4 suits are red (hearts and diamonds), so that would be 2 x 13, plus the 2 5's from the black suits. A total of (2 x 13) + 2 = 28/52, or 7/13.
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by pkw209 » Wed Apr 21, 2010 4:41 pm
Yup, that's right! Also, it's a different method from how I solved it.
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by indiantiger » Wed Apr 21, 2010 5:18 pm
P(RED CARD) = 26/52
P(5 CARD) = 4/52
P(5 and RED CARD) = 2/52

overall probability

P(RED CARD or 5 CARD) = 26/52+4/52-2/52 = 28/52 = 7/13 (Answer)

I hope this helps
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