# Math Help - Social Security Number/Birthday Paradox problem

1. ## Social Security Number/Birthday Paradox problem

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.

$P(A\cup B)=P(A)+P(B)-P(A\cap B)$