Question

Из слова <<статистика>> случайным образом выбирается одна буква.Какова вероятность,что будет выбрана буква,которая встречается в слове <<статистика>> ровно два раза?

Answer 1

5/10=0.5 потому что пять пар одинаковых букв и они могут попасться с такой вероятностью 

Answer 2

Calculating the Probability of Choosing a Letter

To calculate the probability of choosing a letter that appears exactly twice in the word "статистика," we can follow these steps:

1. Count the Total Number of Letters in the Word "статистика": - The word "статистика" contains 10 letters.

2. Count the Number of Unique Letters in the Word "статистика": - The unique letters in "статистика" are "с", "т", "а", "и", and "к".

3. Count the Frequency of Each Unique Letter: - "с" appears 2 times - "т" appears 3 times - "а" appears 1 time - "и" appears 2 times - "к" appears 1 time

4. Calculate the Probability: - We want to find the probability of choosing a letter that appears exactly twice in the word "статистика."

Probability Calculation

The probability can be calculated using the formula: \[ P(\text{event}) = \frac{\text{Number of favorable outcomes}}{\text{Total number of outcomes}} \]

In this case, the favorable outcomes are the letters that appear exactly twice in the word "статистика," which are "с" and "и."

The total number of outcomes is the total number of letters in the word "статистика," which is 10.

Therefore, the probability of choosing a letter that appears exactly twice in the word "статистика" is: \[ P(\text{letter appears exactly twice}) = \frac{2 + 2}{10} = \frac{4}{10} = \frac{2}{5} \]

So, the probability is 2/5 or 0.4.

Conclusion

The probability of choosing a letter that appears exactly twice in the word "статистика" is 2/5 or 0.4.