1985 AJHSME Problem 22
Problem
Assume every 7-digit whole number is a possible telephone number except those that begin with or . What fraction of telephone numbers begin with and end with ?
Note: All telephone numbers are 7-digit whole numbers.
Solution
There are a total of possible phone numbers. The first number is 9 and the last number is 0, so two numbers are fixed, making it so that numbers satisfy the conditions. So, the answer is The answer is B.