Question

На карточках написаны цифры 2,3,4,5,6,7,8,9. Наудачу берут две карточки. Какова вероятность, что обе выбранные цифры нечетные. С объяснением пожалуйста

Answer 1

Ответ: 2 к 8

(2/8=1/4)

Answer 2

Відповідь:

60% что возьмешь одну четную а другую не четную 23% что возьмешь две чётные и 17% что возьмешь две не четные

Покрокове пояснення:

Answer 3

Problem Analysis

We are given a set of cards with the numbers 2, 3, 4, 5, 6, 7, 8, and 9 written on them. We randomly select two cards. We need to find the probability that both selected numbers are odd.

Solution

To find the probability, we need to determine the total number of possible outcomes and the number of favorable outcomes.

Total Number of Possible Outcomes: The total number of possible outcomes is the number of ways we can select two cards from the given set of numbers. This can be calculated using the combination formula:

nCr = n! / (r!(n-r)!)

where `n` is the total number of cards (8 in this case) and `r` is the number of cards we want to select (2 in this case).

Using the combination formula, we can calculate the total number of possible outcomes.

Number of Favorable Outcomes: The number of favorable outcomes is the number of ways we can select two odd numbers from the given set. We can calculate this by counting the number of odd numbers in the set and using the combination formula.

Let's calculate the total number of possible outcomes and the number of favorable outcomes.

Calculation

Total number of possible outcomes: ``` n = 8 (total number of cards) r = 2 (number of cards to select)

nCr = 8! / (2!(8-2)!) = 8! / (2!6!) = (8 * 7) / (2 * 1) = 28 ```

Number of favorable outcomes: ``` Number of odd numbers in the set = 4 (3, 5, 7, 9)

r = 2 (number of cards to select)

nCr = 4! / (2!(4-2)!) = 4! / (2!2!) = (4 * 3) / (2 * 1) = 6 ```

Probability Calculation

Now that we have the total number of possible outcomes (28) and the number of favorable outcomes (6), we can calculate the probability of selecting two odd numbers.

Probability = Number of favorable outcomes / Total number of possible outcomes
           = 6 / 28
           = 3 / 14

Therefore, the probability of selecting two odd numbers from the given set is 3/14.

Conclusion

The probability of selecting two odd numbers from the given set of cards (2, 3, 4, 5, 6, 7, 8, 9) is 3/14.