You need to select a 5-character password for an account. You may use the digits 0-9 or the lower case letters a-z. You may repeat digits or letters. How many possible passwords are there?

1 Answer
Oct 16, 2015



Since the digits are ten, and the letters are twenty-six, we have thirty-six possible character in total.

You can repeat characters, so every place is independent on the content of the others. This means that you have #36# choices for the character in the first place, #36# for the second, and so on. This means #36*36*36*36*36# in total, which is #36^5#.