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In a standard deck of cards, the jack, queen, and king are "face cards." you draw a card from a standard deck. your friend peeks and lets you know that your card is a face card. what is the probability that it is not a king given that it is a face card? leave your answer as a fraction

User Sushanth
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2 Answers

3 votes
If the Ace is a face card, then the answer will be 16/52 or 4/13 simplified.
If the Ace is NOT a face card, then the answer will be 12/52 or 3/13 simplified.
User Freespace
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6 votes

Answer:
(2)/(3)

Explanation:

Total number of cards in a deck = 52

Number of face cards = 12 ( 4 King + 8 others)

The probability that a card is face card P(Face card)=
\frac{\text{Number of face cards }}{\text{Total cards}}


\\\\=(12)/(52)=(3)/(13)

Number of cards are not king = 8

The probability that a card is face card are not King :

P( Face card and not king )=
\frac{\text{Number of face cards are not King}}{\text{Total cards}}


\\\\=(8)/(52)=(2)/(13)

Using conditional probability formula ,


\text{P(Not king}|\text{ Face card})=\frac{\text{P( Face card and not king )}}{\text{ P(Face card)}}


=((2)/(13))/((3)/(13))=(2)/(3)

Hence, the probability that it is not a king given that it is a face card
=(2)/(3)

User Bracher
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