H hcc221 New member Joined Sep 24, 2009 Messages 12 Dec 5, 2009 #1 How do you calculate the probability OF and ODDS of picking a black card or an ace cards? i think the formula for it is P(e)/ P(e') there's 26 black cards and 4 ace cards. the part of the question with "or" got me confused
How do you calculate the probability OF and ODDS of picking a black card or an ace cards? i think the formula for it is P(e)/ P(e') there's 26 black cards and 4 ace cards. the part of the question with "or" got me confused
G galactus Super Moderator Staff member Joined Sep 28, 2005 Messages 7,203 Dec 5, 2009 #2 The probability of a black card OR an Ace are not mutually exclusive. We have to subtract the black Aces. otherwise, we double count. \(\displaystyle \frac{26}{52}+\frac{4}{52}-\frac{2}{52}=\frac{28}{52}=\frac{7}{13}\) Odd is the ratio of for and against. \(\displaystyle 28:24=7:6\) is the odds. 28+24=52. 28 FOR and 24 AGAINST
The probability of a black card OR an Ace are not mutually exclusive. We have to subtract the black Aces. otherwise, we double count. \(\displaystyle \frac{26}{52}+\frac{4}{52}-\frac{2}{52}=\frac{28}{52}=\frac{7}{13}\) Odd is the ratio of for and against. \(\displaystyle 28:24=7:6\) is the odds. 28+24=52. 28 FOR and 24 AGAINST
