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11 votes
11 votes
Urgently plsss A randomly generated password contains four characters. Each of the four characters is either a lowercase letter or a digit from 0–9. Each character in the password cannot be used more than once.

What is the approximate probability that exactly one of the four characters will be a number?

1%
11%
28%
44%

User Thomas Geritzma
by
3.1k points

2 Answers

22 votes
22 votes

Answer:

Explanation:

Sample space is 36C4

Now, we want to know all of the combinations that have 1 digit in it.

So, we can have one here:

1XXX

X1XX

XX1X

XXX1

But we have 10 different digits to choose from. So, we need to introduce the combination term, nCr, where n is a list of all digits and r is how many we want.

Since we only want one, we will need 10C1 for the number of digits. But we need to choose three lowercases, so it becomes 10C1 × 26C3

Since it's a probability question, we need to divide that by our sample space, 36C4, and our percentage becomes 44%

User Kevin Hoerr
by
3.3k points
25 votes
25 votes

Answer:

28%

Explanation:

It is not 44%. I put that and it was wrong.

Urgently plsss A randomly generated password contains four characters. Each of the-example-1
User Hemant Tank
by
2.9k points