There is derivation for birthday problem solution here
Birthday problem - Wikipedia, the free encyclopedia
You can follow the same steps for SSN (assume any digits between 000 and 999 inclusive are equally likely), and then use
What is the probability that out of 10 people randomly selected that either at least 2 will have the same birthday or at least 2 will have the same last 3 digits of there social security number???
I know there is an 11.7% chance of having the same birthday, but where to go from there i have no clue.
There is derivation for birthday problem solution here
Birthday problem - Wikipedia, the free encyclopedia
You can follow the same steps for SSN (assume any digits between 000 and 999 inclusive are equally likely), and then use