Every Card In A Deck Of Cards Is A Face Card Ie Jack

Every Card In A Deck Of Cards Is Either A Face Card Ie Jack Queen

Every card in a deck of cards is either a face card (i.e., Jack, Queen or King) or a non-face card (i.e., Ace, 2,…, 10). A box contains nine non-face cards and one face card. A second box contains one non-face and five face cards. One card is removed from each box at random and without replacement. All of the remaining cards are put into a third box. Determine the probability that a card drawn at random from the third box is a face card.

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The problem involves calculating the probability of drawing a face card from a combined set of remaining cards after particular cards are removed from two initial boxes. To approach this problem accurately, it is essential to understand the initial compositions of both boxes, the process of removal, and how these affect the probability in the final combined collection.

Initially, Box 1 contains 9 non-face cards and 1 face card, totaling 10 cards. Box 2 contains 1 non-face card and 5 face cards, totaling 6 cards. One card is randomly removed from each box without replacement, which influences the composition of each remaining set.

We analyze all possible cases for the cards removed from both boxes: the removal can be either a face card or a non-face card from each box. For Box 1, the probability of removing a face card is 1/10, and a non-face card is 9/10. For Box 2, the probability of removing a face card is 5/6, and a non-face card is 1/6.

After the removal, the contents of each box change accordingly:

  • Box 1 now has 8 non-face and 0 or 1 face cards depending on what was removed.
  • Box 2 has 0 or 1 non-face and 4 or 5 face cards depending on the removal.

The remaining cards from both boxes are combined into a third box. We need to evaluate the probability that a randomly drawn card from this third box is a face card, considering all possible scenarios for the initial removals.

Let's detail each case:

Case 1: Face card removed from Box 1 and face card removed from Box 2

Probability of this case: (1/10) * (5/6) = 5/60 = 1/12.

Remaining cards:

- Box 1: 9 non-face (since face was removed)

- Box 2: 1 non-face, 4 face cards remain

Total remaining cards: 9 + 1 + 4 = 14

Number of face cards remaining: 4

Probability of drawing a face card from this combined set: 4 / 14 = 2 / 7.

Case 2: Face card removed from Box 1, non-face removed from Box 2

Probability: (1/10) * (1/6) = 1/60.

Remaining cards:

- Box 1: 9 non-face (since face was removed)

- Box 2: 0 non-face, 5 face cards remain

Total remaining cards: 9 + 0 + 5 = 14

Number of face cards remaining: 5

Probability: 5 / 14.

Case 3: Non-face card removed from Box 1, face card removed from Box 2

Probability: (9/10) * (5/6) = 45/60 = 3/4.

Remaining cards:

- Box 1: 8 non-face, 1 face card remaining

- Box 2: 1 non-face, 4 face cards remaining

Total remaining cards: 8 + 1 + 1 + 4 = 14

Number of face cards: 1 + 4 = 5

Probability: 5 / 14.

Case 4: Non-face card removed from Box 1, non-face card removed from Box 2

Probability: (9/10) * (1/6) = 9/60 = 3/20.

Remaining cards:

- Box 1: 8 non-face, 1 face card remaining

- Box 2: 0 non-face, 5 face cards remaining

Total remaining cards: 8 + 1 + 0 + 5 = 14

Number of face cards: 1 + 5 = 6

Probability: 6 / 14 = 3 / 7.

To find the overall probability that a randomly selected card from the third box is a face card, we calculate the weighted sum of the face card probabilities across all scenarios:

Total probability = (Probability of case 1 * probability of drawing face card in case 1)

+ (probability of case 2 * probability of drawing face card in case 2)

+ (probability of case 3 * probability of drawing face card in case 3)

+ (probability of case 4 * probability of drawing face card in case 4)

Calculating each term:

  • Case 1: (1/12) * (2/7) = 2/84 = 1/42
  • Case 2: (1/60) * (5/14) = 5/840 = 1/168
  • Case 3: (3/4) (5/14) = (3/4)(5/14) = 15/56
  • Case 4: (3/20) * (3/7) = 9/140

Express all fractions with a common denominator to sum them precisely:

Common denominator: 840 (least common multiple of denominators 42, 168, 56, 140)

  • Case 1: 1/42 = 20/840
  • Case 2: 1/168 = 5/840
  • Case 3: 15/56 = (15 15) / (56 15) = 225/840
  • Case 4: 9/140 = (9 6) / (140 6) = 54/840

Summing all: 20 + 5 + 225 + 54 = 304 over 840.

Simplify the fraction: 304 / 840 = (because both are divisible by 4) = 76 / 210, which further reduces to 38 / 105.

Therefore, the overall probability that a randomly drawn card from the third box is a face card is 38/105.

This detailed analysis highlights how the process of random removals influences the composition of the remaining cards and ultimately affects the probability of drawing a face card. The final probability, simplified to lowest terms, is approximately 0.3619 or 36.19%, reflecting the combined effects of all possible scenarios.

References

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