Using the Fundamental Counting Theorem, it is found that 3,250,000,000 phone numbers are possible.
It is a theorem that states that if there are n things, each with [tex]n_1, n_2, \cdots, n_n[/tex] ways to be done, each thing independent of the other, the number of ways they can be done is:
[tex]N = n_1 \times n_2 \times \cdots \times n_n[/tex]
In this problem:
Hence:
[tex]T = 325 \times 10^7 = 3,250,000,000[/tex]
3,250,000,000 phone numbers are possible.
More can be learned about the Fundamental Counting Theorem at https://brainly.com/question/24314866