Question
Your password for a given website is made up of three letters followed by
four numbers. Find the number of possible passwords if there are no
restrictions on what three letters and what four numbers can be used.
four numbers. Find the number of possible passwords if there are no
restrictions on what three letters and what four numbers can be used.
Answers
matt
Pls check if my answer is correct
26C3*10C4
=26!/(26-3)!3! . 10!/(10-4)!4!
= 26*25*24*23!/23!*6 . 10*9*8*7*6!/6!*4*3*2*1
=15600/6 * 5040/24
=2600*210
=546000
26C3*10C4
=26!/(26-3)!3! . 10!/(10-4)!4!
= 26*25*24*23!/23!*6 . 10*9*8*7*6!/6!*4*3*2*1
=15600/6 * 5040/24
=2600*210
=546000
bobpursley
I didn't see that letters or numbers cant be used more than once.
26*26*26*26*10*10*10*10
As I read it AAAA0000 is allowed, your number didn't include those.
26*26*26*26*10*10*10*10
As I read it AAAA0000 is allowed, your number didn't include those.
matt
Thanks