00:01
On this problem, we are told that the password for a computer system consists of eight distinct alphabetic characters.
00:08
We want to find the number of passwords possible that contain the letters word together, but in any order.
00:16
Now, this is a permutation problem, and permutation problems have us deal with factorials.
00:22
And so factorials, just has some background.
00:26
In factorial is n times n minus 1 times n minus 2, 1, 1 down to 3 times.
00:34
Times 2 times 1.
00:38
Now this password here contains 8 letters, but we want the letters w -o -r -d to be together and so what we are going to do is treat that as one word, treat them as conjoined.
01:02
We treat them as conjoined...