A software program is designed to generate password codes using alphabet from A to J, how many 4-alphabet password codes can the program generate? (please note: the alphabets are not allowed to repeat itself.)
A software program is designed to generate password codes using alphabet from A to J, how many 4-alphabet password codes can the program generate? (please note: the alphabets are not allowed to repeat itself.)?
Answer: A to J there are 10 aplhabets.
Each password is 4 digits length.
Every time you create a password you should pick 4 different letters so that you avoid repetition.
10C4 = 10!/6! * 4! = 210
210 is the correct answer
May I know the IMO?
















