Conditional Probability on Cards of the Same Suit











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A normal deck of 52 playing cards is well shuffled and then 4 cards are dealt to Ann and 4 cards ar dealt to Bob. Ann looks at her c that all 4 of them are from the same suit, that suit being hearts. She is interested in the probability that Bob also has 4 cards that belong to a single suit, allowing for her knowledge of the cards she holds.



Please correct my answer if it is incorrect:
$$text{Probability}=P(text{Bob has all hearts} |text{Ann has all hearts})+P(text{Bob has all clubs/spades/diamonds}|text{Ann has all hearts})$$



$$=frac{binom{9}{4}}{binom{48}{4}}+frac{binom{3}{1}timesbinom{13}{4}}{binom{48}{4}}$$



$$=frac{757}{64860}$$



I am aware that this is a conditional probability, but I was unsure how to apply Bayes' Theorem in this scenario.










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  • correct except $^{48}C_4$ in denominator
    – idea
    6 mins ago















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A normal deck of 52 playing cards is well shuffled and then 4 cards are dealt to Ann and 4 cards ar dealt to Bob. Ann looks at her c that all 4 of them are from the same suit, that suit being hearts. She is interested in the probability that Bob also has 4 cards that belong to a single suit, allowing for her knowledge of the cards she holds.



Please correct my answer if it is incorrect:
$$text{Probability}=P(text{Bob has all hearts} |text{Ann has all hearts})+P(text{Bob has all clubs/spades/diamonds}|text{Ann has all hearts})$$



$$=frac{binom{9}{4}}{binom{48}{4}}+frac{binom{3}{1}timesbinom{13}{4}}{binom{48}{4}}$$



$$=frac{757}{64860}$$



I am aware that this is a conditional probability, but I was unsure how to apply Bayes' Theorem in this scenario.










share|cite|improve this question






















  • correct except $^{48}C_4$ in denominator
    – idea
    6 mins ago













up vote
0
down vote

favorite









up vote
0
down vote

favorite











A normal deck of 52 playing cards is well shuffled and then 4 cards are dealt to Ann and 4 cards ar dealt to Bob. Ann looks at her c that all 4 of them are from the same suit, that suit being hearts. She is interested in the probability that Bob also has 4 cards that belong to a single suit, allowing for her knowledge of the cards she holds.



Please correct my answer if it is incorrect:
$$text{Probability}=P(text{Bob has all hearts} |text{Ann has all hearts})+P(text{Bob has all clubs/spades/diamonds}|text{Ann has all hearts})$$



$$=frac{binom{9}{4}}{binom{48}{4}}+frac{binom{3}{1}timesbinom{13}{4}}{binom{48}{4}}$$



$$=frac{757}{64860}$$



I am aware that this is a conditional probability, but I was unsure how to apply Bayes' Theorem in this scenario.










share|cite|improve this question













A normal deck of 52 playing cards is well shuffled and then 4 cards are dealt to Ann and 4 cards ar dealt to Bob. Ann looks at her c that all 4 of them are from the same suit, that suit being hearts. She is interested in the probability that Bob also has 4 cards that belong to a single suit, allowing for her knowledge of the cards she holds.



Please correct my answer if it is incorrect:
$$text{Probability}=P(text{Bob has all hearts} |text{Ann has all hearts})+P(text{Bob has all clubs/spades/diamonds}|text{Ann has all hearts})$$



$$=frac{binom{9}{4}}{binom{48}{4}}+frac{binom{3}{1}timesbinom{13}{4}}{binom{48}{4}}$$



$$=frac{757}{64860}$$



I am aware that this is a conditional probability, but I was unsure how to apply Bayes' Theorem in this scenario.







probability combinations






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asked 21 mins ago









An Invisible Carrot

698




698












  • correct except $^{48}C_4$ in denominator
    – idea
    6 mins ago


















  • correct except $^{48}C_4$ in denominator
    – idea
    6 mins ago
















correct except $^{48}C_4$ in denominator
– idea
6 mins ago




correct except $^{48}C_4$ in denominator
– idea
6 mins ago










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$P(A)$ = P(Anne has all hearts) =$$frac{^{13}C_4}{^{52}C_4}$$
$P(B)$ = P(Bod has same suite) =$$frac{^{13}C_4cdot 4}{^{52}C_4}$$
$$P(B/A)=frac{P( A ∩ B)}{P(A)}$$
Using:




P(A ∩ B)=$$frac{^{13}C_4 cdot 3+ ^{9}C_4}{^{52}C_4}$$




You get: $$P(B/A)=frac {^{13}C_4 cdot 3+ ^{9}C_4}{^{13}C_4}$$






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    $P(A)$ = P(Anne has all hearts) =$$frac{^{13}C_4}{^{52}C_4}$$
    $P(B)$ = P(Bod has same suite) =$$frac{^{13}C_4cdot 4}{^{52}C_4}$$
    $$P(B/A)=frac{P( A ∩ B)}{P(A)}$$
    Using:




    P(A ∩ B)=$$frac{^{13}C_4 cdot 3+ ^{9}C_4}{^{52}C_4}$$




    You get: $$P(B/A)=frac {^{13}C_4 cdot 3+ ^{9}C_4}{^{13}C_4}$$






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      $P(A)$ = P(Anne has all hearts) =$$frac{^{13}C_4}{^{52}C_4}$$
      $P(B)$ = P(Bod has same suite) =$$frac{^{13}C_4cdot 4}{^{52}C_4}$$
      $$P(B/A)=frac{P( A ∩ B)}{P(A)}$$
      Using:




      P(A ∩ B)=$$frac{^{13}C_4 cdot 3+ ^{9}C_4}{^{52}C_4}$$




      You get: $$P(B/A)=frac {^{13}C_4 cdot 3+ ^{9}C_4}{^{13}C_4}$$






      share|cite























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        up vote
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        down vote









        $P(A)$ = P(Anne has all hearts) =$$frac{^{13}C_4}{^{52}C_4}$$
        $P(B)$ = P(Bod has same suite) =$$frac{^{13}C_4cdot 4}{^{52}C_4}$$
        $$P(B/A)=frac{P( A ∩ B)}{P(A)}$$
        Using:




        P(A ∩ B)=$$frac{^{13}C_4 cdot 3+ ^{9}C_4}{^{52}C_4}$$




        You get: $$P(B/A)=frac {^{13}C_4 cdot 3+ ^{9}C_4}{^{13}C_4}$$






        share|cite












        $P(A)$ = P(Anne has all hearts) =$$frac{^{13}C_4}{^{52}C_4}$$
        $P(B)$ = P(Bod has same suite) =$$frac{^{13}C_4cdot 4}{^{52}C_4}$$
        $$P(B/A)=frac{P( A ∩ B)}{P(A)}$$
        Using:




        P(A ∩ B)=$$frac{^{13}C_4 cdot 3+ ^{9}C_4}{^{52}C_4}$$




        You get: $$P(B/A)=frac {^{13}C_4 cdot 3+ ^{9}C_4}{^{13}C_4}$$







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        answered 7 mins ago









        idea

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