Question

You must create a password for a website. The password can use any digits

from 0 to 9 and/or any letters of the alphabet. The password is not case
sensitive. A password must be at least 6 characters to a maximum of 8
characters long. Each character can be used only once in the password.
How many different passwords are possible?

Answer 1

2,120,214,488,560

Explanation:

Step 1: Determine the number of characters in the password. Since the password can be between 6 and 8 characters long, there are three possible values: 6, 7, or 8.

Step 2: Determine the number of characters that can be used in the password. There are 10 digits and 26 letters in the alphabet, for a total of 36 characters.

Step 3: Determine the number of ways to choose the first character of the password. Since the first character can be any of the 36 characters, there are 36 possible choices.

Step 4: Determine the number of ways to choose the second character of the password. Since the second character can be any of the remaining 35 characters (since each character can be used only once), there are 35 possible choices.

Step 5: Continue this process until all characters in the password have been chosen.

Step 6: Add up the total number of possible passwords for each password length (6, 7, and 8) to get the final answer.

Using this method, we can calculate the total number of possible passwords as follows:

For passwords with 6 characters:

36 * 35 * 34 * 33 * 32 * 31 = 1,735,488,560

For passwords with 7 characters:

36 * 35 * 34 * 33 * 32 * 31 * 30 = 59,814,480,000

For passwords with 8 characters:

36 * 35 * 34 * 33 * 32 * 31 * 30 * 29 = 2,058,911,520,000

Therefore, the total number of possible passwords is:

1,735,488,560 + 59,814,480,000 + 2,058,911,520,000 = 2,120,214,488,560