*The telephone numbers for a region of a state have an area code of 570. The next seven digits represent the local telephone numbers for that region. A local telephone number cannot begin with a 0 or 1. Your cousin lives within the given area code.*

What is the probability of not randomly generating your cousin’s telephone number? Explain.

I understand the denominators - one 8 and 10 to the sixth power - but not the numerators. I don't understand why the chance of randomly generating a number and the chance of NOT randomly generating a number are the same thing... (are they the same thing???)

Thanks in advance!