Question

social security number contains nine digits 0 0 0 0 0 0 0 0 0 how many different Social Security numbers can be formed using in a in a numerals from 0-9

Answer 1

9 digits x 9 numbers = 81

Answer 2

First spot: 9 choices (0-9)
Second spot: 9 choices (0-9)
Third spot: 9 choices (0-9)
.
.
.
Ninth spot: 9 choices (0-9)

There are 9 choices for each digit, meaning we need to compute 9^9 to figure out how many possible social security numbers there are.

9^9 = 387420489 possible social security numbers