PLEASE HELP ME!!
Consider a 7 digit number in the form ABC-XXXX where A is 2-9 and X, B, and C can be
any digit 0-9. Additionally B and C cannot both equal 1 since these values are designated for other purposes such as services like 911. Lastly 555-0100 through 555-0199 are reserved for fictional uses such as in television shows or movies.
According to these conditions, how many 7-digit numbers are possible in a single area
code?