A company assign a unique 3 digit telephone extension to each of its employees. What is the maximum number of employees of the company's telephone sustem will accomodate?
1) the first digit of each extension is restricted to the 2 through 8, there are no restriction on the second and third digit.
2) the digit 9 is used to access an outside telephone line.
Please explain ur answer.
I don't see relevance of condition 2 since the first digit can not be equal to 9 anyway.
first digit: 7 options, second digit 10 options, third digit 10 options -> 700 employees