00:01
In this question we are given that a computer password is 9 characters long and the password consists of one letter followed by 8 digits and no repeats are a lot of the letters and digits.
00:15
And we want to find the number of such possible passwords.
00:19
Now take note that the digits here are chosen without replacement because no repeats.
00:33
That also we take note that the arrangement of the digits are important as, for example, 1, 2, 3, 4, 6, 7, 8 is different from 8, 7, 6, 5, 4, 3, 2, 1.
00:51
So arrangements of digits are important.
00:54
So the order is important.
01:00
Order of digits is important.
01:06
So without replacement, order of digit important, we'll be using permutation for the digit part.
01:11
And that's the one with p.
01:14
So let me draw 8 slots 8 slots for the digits here and one slot here for the letter...
