A social security number consists of nine digits. How many different social security numbers are possible if repetition of digits is permitted?

Question

Oh goodness, I'm not sure what number to start with :(

Answer 1

in each position you could place 9 different digits.
So the total number of ways = 9^9 = .....

Answer 2

9^9 = 387,420,489 different social security numbers are possible??

Answer 3

correct

Answer 4

okay great! thanks :)