SOLUTION: A typical Social Security number is 555-47-5593. How many Social Security numbers are possible if the first three digits cannot be 1?

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Question 1205570: A typical Social Security number is 555-47-5593. How many Social Security numbers are possible if the first three digits cannot be 1?
Answer by ikleyn(52777) About Me  (Show Source):
You can put this solution on YOUR website!
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A typical Social Security number is 555-47-5593. How many Social Security numbers are possible
if the first three digits cannot be 1?
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If all nine-digit Security numbers be allowed from  000-00-0000  till  999-99-9999,
the amount of such numbers would be  1,000,000,000 (one billion).


But, according to the problem,  Security numbers from  111-00-0000  to  111-99-9999 are prohibited.
The amount of the prohibited numbers is  1,000,000  (one million).


So, the  ANSWER  to the problem's question is this difference

         1,000,000,000 - 1,000,000 = 999,000,000.

Solved.