Posted by **Jen** on Tuesday, July 26, 2011 at 5:08pm.

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

Is it 9^10?? 10 numbers correct?

- Math-New Questions -
**Count Iblis**, Tuesday, July 26, 2011 at 5:23pm
If you intepret the string of digits as numbers, then the numbers are between 10^8 and 10^9 -1, so the answer is:

10^9 - 1 - (10^8 - 1) =

10^9 - 10^8

- Math-New Questions -
**Jen**, Tuesday, July 26, 2011 at 7:08pm
oooooh i totally got lost on this....

- Math-New Questions -
**Anonymous**, Tuesday, July 26, 2011 at 7:42pm
We can use the rule of product:

the first number we choose from 1 to 9,

the 2nd, 3rd,...,9th from 0 to 9.

So the number is

9*10*10*...*10=9*10^8 (=10^9-10^8)

- Math-New Questions -
**Jen**, Tuesday, July 26, 2011 at 8:41pm
SO ITS 1000000000-100000000 = 900000000??

- Math-New Questions -
**Anonymous**, Tuesday, July 26, 2011 at 9:39pm
yes

## Answer This Question

## Related Questions

- Math - Social Security Numbers A social security number consists of nine digits...
- Math - A social security number consists of nine digits. How many different ...
- College Mathematics - Counting principles and permutations. A social security ...
- College Mathematics - Counting Principles and Permutation. A social security ...
- math - a social security number contains nine digits such as 074-66-7795. how ...
- math - A typical Social Security number is 555-47-5593. How many Social Security...
- Math - A Social Security number has seven digits. How many Social Security ...
- Math - 1.) A security code has seven characters. Each code begins with two ...
- Information Technology - Draw a flowchart for a program that allows the user to...
- Government US - Which of the following is true of social security and Medicare? ...

More Related Questions