explain why social security numbers are 9 digits long

Question

there are approximately 317 million people in the united states. compute and use log(100,000,000) and log (1,000,000,000) to explain why social security numbers are 9 digits long

Answer 1

Log (100,000,000) = 8 since 10⁸= 100,000,000.

Log (1,000,000,000) = 9 since 10⁹ = 1,000,000,000.

 

Thus, it requires 9 digits to represent 317M+ individuals with a unique number [000-00-0000 to 999-99-9999, with reserved values],