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4. You have a deck of 40 number cards: five of each number 2 to 9. You shuffle the deck, pick a card, look at it, return it to the deck, and then repeat for a second card. Determine each theoretical probability. a) sum is 12 b) difference is less than 5 c) product is odd​

4. You have a deck of 40 number cards: five of each number 2 to 9. You shuffle the-example-1
User Samuele
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To determine the theoretical probabilities, we'll analyze the different possible outcomes for each case.

Total number of cards = 40 (5 cards for each number from 2 to 9)

a) Sum is 12:

There are several combinations of cards that can result in a sum of 12:

  • 3 and 9
  • 4 and 8
  • 5 and 7
  • 7 and 5
  • 8 and 4
  • 9 and 3

Total favorable outcomes = 6 (since there are 6 possible combinations)

Total possible outcomes (since you're drawing two cards) = 40 * 40 = 1600

Probability (sum is 12) = (Number of favorable outcomes) / (Total possible outcomes)

Probability (sum is 12) = 6 / 1600 = 0.00375

b) Difference is less than 5:

There are several combinations of cards that can result in a difference less than 5:

  • 2 and 3
  • 3 and 2
  • 3 and 4
  • 4 and 3
  • 4 and 5
  • 5 and 4
  • 5 and 6
  • 6 and 5
  • 6 and 7
  • 7 and 6
  • 7 and 8
  • 8 and 7
  • 8 and 9
  • 9 and 8

Total favorable outcomes = 14

Total possible outcomes = 1600

Probability (difference is less than 5) = 14 / 1600 = 0.00875

c) Product is odd:

For the product to be odd, one or both of the numbers drawn must be odd. Since there are five odd numbers (3, 5, 7, 7, 9), and each number has five cards, the total number of favorable outcomes is 5 + 5 + 5 + 5 + 5 = 25.

Total possible outcomes = 1600

Probability (product is odd) = 25 / 1600 = 0.015625

To summarize:

  • a) Probability (sum is 12) ≈ 0.00375
  • b) Probability (difference is less than 5) ≈ 0.00875
  • c) Probability (product is odd) ≈ 0.015625
User Rorofromfrance
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