Question 461124: you randomly select a card from a 52-card deck. What is the probability that the card is either an 8 or black?
Answer by richard1234(7193)   (Show Source):
You can put this solution on YOUR website! I'll assume that the card can be an 8, a black, or both.
There are 26 black cards and four 8's in a standard deck. Using Inclusion-Exclusion principle, the number of cards that are black and/or an 8 is 26 + 4 - 2 (2 being the number of black 8's) = 28. Hence the probability is 28/52 = 7/13.
If we do not want black 8's, we simply subtract off the two black 8's, leaving 26 cards out of 52. The probability in this case would be 26/52 = 1/2.
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