eli5: with social security numbers you only have 9 digits to choose from and only so many number orders to choose from. How do no 2 people have the same order of numbers?

Question

eli5: with social security numbers you only have 9 digits to choose from and only so many number orders to choose from. How do no 2 people have the same order of numbers?

In: 0

Answer 1

With 9 digits, there are a billion combinations, which is about 3 times more than the current US population.