00:01
In this problem it is said that a 5 character password can be made using lowercase letters, the digits from 0 to 9, and 9 special characters.
00:09
The first character must be a letter, the last character needs to be a digit, and we need to determine how many passwords are possible if no repetitions are possible.
00:19
So we have 1, 2, 3, 4, 5 characters.
00:23
Now the first character must be a letter.
00:26
There are a total of 26 lowercase letters, so there are 26 options to choose from when selecting this first character.
00:33
And the last character needs to be a digit.
00:35
Now there are 10 digits from 0 to 9, so there are 10 options for this character.
00:40
Now consider this second character.
00:42
Now there is no restriction on this character except for the fact that no repetitions are possible...
