There are 7 digits in phone number. The first digit cannot be 0 and 1. So first digit can be filled by 8 numbers (from 2 to 9). Remaining 6 digits of the phone number can be filled by all 10 number (0 to 1).
The possible number of 7 digit phone numbers are,
[tex]8\cdot10\cdot10\cdot10\cdot10\cdot10\cdot10=8,000,000[/tex]
So 8,000,000 different numbers are possible.
Answer: 8,000,000
