Question

Пароль в компьютерную базу данных состоит из 7 цифр какова вероятность правильного набора с первого раза если комбинация цифр образует возростающую последовательность

Answer 1

Р=1/7*1/6*1/5*1/4*1/3*1/2*1=1/5040

Answer 2

Probability of Correctly Guessing a 7-Digit Password with Increasing Sequence

The probability of correctly guessing a 7-digit password with an increasing sequence can be calculated by considering the number of possible combinations.

Assumptions: - The digits in the password must form an increasing sequence. - The digits can range from 0 to 9.

Calculation

The number of ways to choose 7 digits from 0 to 9 without repetition is given by the combination formula:

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

Where: - n = 10 (possible digits 0-9) - r = 7 (number of digits in the password)

The number of increasing sequences of 7 digits chosen from 0 to 9 can be calculated using combinatorics.

Probability Calculation

The probability of correctly guessing the password on the first attempt can be calculated by dividing the number of increasing sequences by the total number of possible combinations.

Probability = (Number of Increasing Sequences) / (Total Possible Combinations)

Result

The probability of correctly guessing a 7-digit password with an increasing sequence on the first attempt is 1 in 120.

This is calculated as follows: - Number of Increasing Sequences = 120 - Total Possible Combinations = 10,000,000