Two cards are drawn from a fifty-two-card deck. What is the probability that the draw will yield an ace and a face card?
I havent worked with probability in like a year XD i forgot how to :P
Think of it like this. There are 4 face/ace cards to every suit.
That is true
4 cards times 4 gives us 16. There are 16 out of 56 cards that are face cards.
I mean 52.
yeah I know
there are a couple ways to do this but first we need to know does it mean "and ace and then a face card" which is easy or does it mean "one of the two cards is and ace, the other is a face card" which is somewhat harder
Sorry ^^''.
ok
And true, @satellite73.
But if he meant the way I did it, then its a simple 16:52
oh no
But its not done yet. Find the common factor.
Did I mess up somewhere? o.o''
first card is an ace \[\frac{4}{52}\] second card is a face card given that the first card is an ace \[\frac{12}{51}\] AND \[\frac{4}{52}\times \frac{12}{51}\]
that is "first ace, then face card" which might not be what the question is asking
one is a face card, the other is an ace \[\frac{4\times 12}{\binom{52}{2}}\]
There is only an ace and a face card. I just asked my teacher
Only one ace and one face?
yes
\(\binom{52}{2}=\frac{52\times 51}{2}=1326\) your answer is \[\frac{4\times 12}{1326}\]
Alright Satellite how did you get that answer
the denominator is all the ways you can choose two cards out of fifty two i.e. "fifty two choose 2" written as \(\binom{52}{2}\) or sometimes \(_{52}C_2\) or even \(^{52}C_2\) and computed via \[\frac{52\times 51}{2}\]
the numerator is the number of ways you can pick one ace out of four, which is \(4\) times the number of ways you can pick 1 facecard out of 12, which is 12
Like @satellite73 said, \[P(1\text{ ace}\cap1\text{ face})=\frac{P(1\text{ ace})\cdot P(1\text{ face})}{P(2\text{ cards from deck}}=\frac{\binom 41\binom{12}1}{\binom{52}2}\]
thanks
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