Question

How many social security numbers are available if the only restriction is that the number 000-00-0000 cannot be assigned?

Answer 1

There are 999,999,999 possible Social Security number combinations, subtracting one from the 10^9 available combinations to account for the restriction against the number 000-00-0000.

Step-by-step explanation:

A Social Security number (SSN) consists of nine digits, traditionally written in the format XXX-XX-XXXX, where each X represents one digit from 0 to 9. When calculating the number of possible SSN combinations, one would consider that each digit position in the SSN can take on any value between 0 and 9, making for 10 possibilities per position. However, we also know that a SSN cannot be 000-00-0000. Hence, the total number of SSN combinations would be:

Total Combinations = 109 (number of combinations for nine digits) - 1 (excluding the number 000-00-0000).

109 equals 1,000,000,000, so removing one for the restricted number results in a total of 999,999,999 possible SSN combinations.

Answer 2

each digit can be 0-9 ( 10 numbers)
there are 9 numbers in a social security number

multiply 10 nine times:
10 x 10 x 10 x 10 x 10 x 10 x 10 x 10 x 10 = 1,000,000,000 ( 1 billion) possibilities.

the restriction is it can't be all zeros so subtract 1 from the total
1,000,000,000 - 1 = 999,999,999 combinations