Question

An internet site requires a 6 character password made up of 2 digits followed by 4 letters where uppercase letters are not the same as lowercase letters. Without repetition of letters or numbers, how many different passwords can be created?

Answer 1

10 choices for the first digit, 9 for the second digit, and now we have to move on to the letter.

Since uppercase letters are different than lowercase, there are 52 letters total. Thus, you have\[10\cdot9\cdot52\cdot51\cdot50\cdot49\]Choices total.

Answer 2

Oh i see, so its not exactly a permutation or combination. Thanks

Answer 3

You're welcome.