How many six-character passwords are possible if (a) characters can be repeated and (b) characters cannot be repeated?

Question

This is a problem where I need to know how many possible outcomes there are. 

Answer 1

What is the set of CHARACTERS from which any individual position of the password may be chosen??

 

Assume that n = # of distinct possible characters.

 

Then:   a) n⁶ is the answer   b) nC6 is the answer.