Question

9 The Social Security number contains nine digits, if the form of 000-00-0000. How many differentSexial Security numbers can be formed using any numerals from 0 to 9?

Answer 1

Each digit has 10 possible values (the numbers from 0 to 9), so in order how many different numbers can be formed, we need to multiply the number of possible values of each digit.

If we have 9 digits, and each digit has 10 possible values, we need to multiply the number 10 by itself 9 times, that is:

$N=10^9$

So the number of different social security numbers is 10^9 (1,000,000,000, one billion)