Social Security Numbers (SSNs) are nine-digits in length. The maximum number of combinations without exclusion is 109, or one billion. However, a number of number combinations are excluded (e.g., 666-xx-xxxx, 000-xx-xxxx, xxx-00-xxxx, xxx-xx-0000, as well as SSNs beginning with most numbers over 733). After excluded combinations are taken into account, the maximum number of combinations is approximately 745 million. According to the Social Security Administration, approximately 442 million SSNs have been assigned, with 5.5 million new numbers assigned each year. At this rate, new numbers can be assigned over the next 52 years (i.e., 2009 through 2061) before reassigning numbers or changing the archetype. Sources: * http://ssa-custhelp.ssa.gov/cgi-bin/ssa.cfg/php/enduser/std_adp.php?p_faqid=86&p_created=955483126&p_sid=CrOQahCj&p_accessibility=0&p_redirect=&p_lva=&p_sp=cF9zcmNoPTEmcF9zb3J0X2J5PSZwX2dyaWRzb3J0PSZwX3Jvd19jbnQ9MjAsMjAmcF9wcm9kcz0mcF9jYXRzPTE2LDU4JnBfcHY9JnBfY3Y9Mi41OCZwX3NlYXJjaF90eXBlPWFuc3dlcnMuc2VhcmNoX25sJnBfcGFnZT0x&p_li=&p_topview=1 * http://en.wikipedia.org/wiki/Social_security_number
10 Combinations (if order doesn't matter). 3,628,800 Possiblilities (if order matters).
how many combinations of 4 numbers are there in 7 numbers
I do personally think that social security numbers are needed to prevent identity theft. Although there are many instances of identity theft, the instances would be greater without social security numbers to help identify citizens with.
200000000
Loss of Soldier's social security numbers
There are: 9C6 = 84 combinations
Allowing leading zeros, 109 or 1 billion.
About 450 million
There are 167960 combinations.
It depends on combinations with how many numbers. There is only one combination of 99 numbers taken from 99.
There are 125970 combinations and I am not stupid enough to try and list them!
No, I do not think that social security numbers should be removed and a new means of identification be initiated. That leaves too many opportunities for error.