a social security number contains nine digits such as 074-66-7795. how many different social security numbers can be formed?
1,000,000,000 different social security numbers can be formed.
To find the number of different social security numbers that can be formed, we need to consider the possible combinations of digits for each position.
Since a social security number contains nine digits, we have the following:
- For the first digit, there are 10 options (0-9) since it can include leading zeroes.
- For the second digit, there are 10 options again, as it can also include leading zeroes.
- For the third digit (the hyphen), there is only 1 option.
- For the fourth digit, there are only 10 options (0-9) since it cannot include leading zeroes.
- For the fifth digit, there are 10 options once again, as it can also include leading zeroes.
- For the third digit (the second hyphen), there is only 1 option.
- For the seventh digit, there are 10 options (0-9) since it cannot include leading zeroes.
- For the eighth digit, there are 10 options once again, as it can also include leading zeroes.
- For the ninth digit, there are 10 options again.
Using the multiplication principle, we can multiply the number of options for each digit together to find the total number of different social security numbers that can be formed:
10 * 10 * 1 * 10 * 10 * 1 * 10 * 10 * 10 = 1,000,000.
Therefore, there are 1,000,000 different social security numbers that can be formed.
To calculate the number of different social security numbers that can be formed, we need to consider the possibilities for each digit separately.
1. The first digit: It cannot be zero since social security numbers do not start with a zero. Therefore, it has 9 possible options (1-9).
2. The second digit: It can be any digit from 0 to 9, so there are 10 options.
3. The third digit: Like the second digit, it can also be any digit from 0 to 9, so there are 10 options.
4. The fourth digit: There are 10 possible options, from 0 to 9.
5. The fifth digit: Again, 10 possible options.
6. The sixth digit: 10 possible options.
7. The seventh digit: 10 possible options.
8. The eighth digit: 10 possible options.
9. The ninth digit: 10 possible options.
To find the total number of different social security numbers that can be formed, we multiply the number of possibilities for each digit:
9 * 10 * 10 * 10 * 10 * 10 * 10 * 10 * 10 = 900,000,000
Therefore, there are 900,000,000 different social security numbers that can be formed.