The first three digits are referred to as an “area code” and specify an individual’s geographic region, with the next seven digits uniquely identifying the individual. Moreover, the first digit of the

7-digit unique identifier must be from 2 to 9 , inclusive, and the two digits immediately after cannot both be 1.

so essentially - want to find out a case where both the 2nd and 3rd digit would not be 1 together. in this case can i say the possible cases =

8 x 10 x 9 x 10 x 10 x 10 x 10 ??