How many five-character code words are there if the first character is always a letter and the other characters are letters and/or digits?

Question

I am pretty sure this has something to do with combination or permutation but I am not sure. please help!

Answer 1

This isn't some fancy formula. It's just blanks:

Here's our code word:

___ ___ ___ ___ ___

26 36 36 36 36

We have a letter in the first position (26 of those)

and a letter or digit in the remaining (36 of those).

multiply them all together to get your answer.