Calculate the possible combinations for an eight-character password Can any when one help me in this question: 
Calculate the possible combinations for;


*

*An eight-character password consisting of upper- and lowercase letters and at least one numeric digit $(0–9)$?

*A ten-character password consisting of upper- and lowercase letters and at least one numeric digit $(0–9)$?
Thanks 

Hint:
(v): One character can be one of 62 (= 26[A-Z]+26[a-z]+10[0-9]) letters, and choosing one character for password is independent of choosing other characters for password.
(vi): #(An alphanumeric password containing at least one numeric digit) = #(An alphanumeric password) - #(An alphanumeric password which not contains any digit) 
