Problem

How many seven-digit telephone numbers are possible if the first two digits cannot be ones or zeros?
64,000,000 telephone numbers

Answer

Expert–verified
Hide Steps
Answer

Final Answer: The total number of possible seven-digit telephone numbers, if the first two digits cannot be ones or zeros, is 6,400,000.

Steps

Step 1 :The problem is asking for the total number of seven-digit telephone numbers possible if the first two digits cannot be ones or zeros.

Step 2 :The first two digits can be any of the 8 remaining digits (2-9), and the remaining 5 digits can be any of the 10 digits (0-9).

Step 3 :Therefore, the total number of possible telephone numbers is calculated as 881010101010.

Step 4 :By calculating the above expression, we get the total number of possible telephone numbers as 64,000,000.

Step 5 :Final Answer: The total number of possible seven-digit telephone numbers, if the first two digits cannot be ones or zeros, is 6,400,000.

link_gpt